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DESCARTES EMBODIED

Reading Cartesian Philosophy through

Cartesian Science

DANIEL GARBER

University of Chicago


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CONTENTS

Acknowledgments page ix

Abbreviations, Citations, and Translations xi

Introduction 1

Part I. Historiographical Preliminaries

1 Does History Have a Future? Some Reflections on

Bennett and Doing Philosophy Historically 13

Part II. Method, Order, and Certainty

2 Descartes and Method in 1637 33

3 A Point of Order: Analysis, Synthesis, and Descartes’

Principles (with Lesley Cohen) 524 J.-B. Morin and the Second Objections 64

5 Descartes and Experiment in the Discourse and Essays 85

6 Descartes on Knowledge and Certainty: From the

Discours to the Principia 111

Part III. Mind, Body, and the Laws of Nature

7 Mind, Body, and the Laws of Nature in Descartes

and Leibniz 133

8 Understanding Interaction: What Descartes Should

Have Told Elisabeth 168

9 How God Causes Motion: Descartes, Divine Sustenance,

and Occasionalism 189

10 Descartes and Occasionalism 203

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11 Semel in vita : The Scientific Background to Descartes’

Meditations 221

12 Forms and Qualities in the Sixth Replies 257

Part IV. Larger Visions

13 Descartes, or the Cultivation of the Intellect 277

14 Experiment, Community, and the Constitution of

Nature in the Seventeenth Century 296

Sources 329

Index333

viii contents


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ABBREVIATIONS, CITATIONS, AND

TRANSLATIONS

Although these essays were originally published at different times, in

different places, and using different abbreviations and conventions of

citation, I have tried to bring a certain amount of consistency to the

collective whole, at least when dealing with the writings of Descartes.

In the essays that follow, I have used the following abbreviations:

AT Descartes, René, Oeuvres de Descartes , ed., Charles Adam

and Paul Tannery, new edition. (11 vols.) Paris: CNRS/Vrin,

1964–74. References by volume number and page (e.g.,

AT VII 74).

CSM Descartes, René, The Philosophical Writings of Descartes , ed.

and trans., John Cottingham, Robert Stoothoff, and DugaldMurdoch (2 vols.). Cambridge: Cambridge University Press,

1984–85. References by volume number and page (e.g.,

CSM II 74).

CSMK Descartes, René, The Philosophical Writings of Descartes Volume

III: The Correspondence , ed. and trans., John Cottingham,

Robert Stoothoff, Dugald Murdoch, and Anthony Kenny.

Cambridge: Cambridge University Press, 1991. Referencesto page numbers (e.g., CSMK 146).

AT remains the standard original-language text, and CSM and CSMK

have become the standard English translations. In some essays, there

are references to both AT and an English translation; more often,

not. Since CSM and CSMK key their texts directly to AT, it should be

xi


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easy enough to move from the AT citations that I usually give to those

translations. Though I do not always cite them, I often do borrow from

them in essays written after they became available. In the earlier essays,

I made some use of earlier translations that they replaced. In par-ticular, some of the earlier pieces in this collection borrow from the

once standard translations of Haldane and Ross1 and the volume of

Descartes’ letters edited and translated by Anthony Kenny 2 (which

metamorphasized into CSMK), as well as the translations of Anscombe

and Geach,3 Laurence J. Lafleur,4 Paul J. Olscamp5 (for the Dioptrics and

Meteors ), and others that are lost in the sands of time and on the shelves

of my library. To these helpful crutches go all the praise and none of the blame: If I have borrowed their mistakes in translation (or, even

worse, made original mistakes of my own), it’s my own damned fault.

In any case, direct references to outdated translations in the original

essays have been eliminated.

I have not tried to revise essays or footnotes in any extensive way.

When I found that I no longer agreed with a view expressed in an essay

I published some years ago, I was more inclined to omit it from this

volume than try to correct it. Also, I have made no attempt to updatethe notes and references. Changes are limited to making the system of

references more consistent from one essay to the next, adding some

cross references to other essays in this volume, and, in the case of one

essay, translating the quotations from Latin and French into English.

I also tried to omit some overlapping passages. However, these essays

were written to be independent and free-standing, and given the inter-

connected themes, some amount of overlap is inevitable.

xii abbreviations, citations, translations

1 Descartes, The Philosophical Works of Descartes , ed. and trans. E. S. Haldane and G. R. T. Ross

(2 vols.). Cambridge: Cambridge University Press, 1911, and often reprinted.

2 Descartes, Philosophical Letters , ed. and trans. Anthony Kenny. Oxford: Oxford University

Press, 1970, later reprinted, Minneapolis: University of Minnesota Press, 1981.

3 Descartes, Philosophical Writings , ed. and trans. E. Anscombe and P. Geach. Edinburgh:

T. Nelson, 1954, and often reprinted.

4 Descartes, Discourse on Method and Meditations , ed. and trans. Laurence J. Lafleur.

Indianapolis: Bobbs-Merrill, 1960. Descartes, Rules for the Direction of the Mind , ed. andtrans. Laurence J. Lafleur. Indianapolis: Bobbs-Merrill, 1961.

5 Descartes, Discourse on Method, Optics, Geometry, and Meteorology , trans. Paul J. Olscamp.

Indianapolis: Bobbs-Merrill, 1965.


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INTRODUCTION

My interest in Descartes was originally piqued when, as a graduate

student, I had to assist in an introduction to philosophy. The Descartes

I was asked to teach the students didn’t make much sense to me; I

couldn’t figure out his point of view, why he was asking the kinds of

questions he was asking, and why he was giving the kinds of answers he was giving. Something about his larger intellectual context seemed to

be missing. But even then I knew that Descartes was deeply involved in

the physical sciences of his day, and even without knowing exactly what

Cartesian science meant, I had a deep suspicion that it was somehow

connected with the philosophical writings I was teaching my under-

graduates, the Meditations and the Discourse on the Method . At the time I

was also very interested in the latest currents in contemporary philos-ophy, particularly the philosophy of Quine. Quine’s enormously influ-

ential “Epistemology Naturalized” had just appeared, and everyone was

talking about a more general naturalization of philosophy and the inti-

mate connection between philosophy and the sciences.1 That gave me

all the more reason to turn to Descartes and his contemporaries, who,

in a sense, took it for granted that there was a continuum between what

we call philosophy and what we consider the sciences.

And so I undertook a serious study of Descartes’ science, as well asthat of his contemporaries. This led me to a number of interesting

observations. I came to see that Descartes’ thought must be understood

in the context of the attempt to reject Aristotelian physics, and replace

1

1 See W. V. O. Quine, Ontological Relativity and Other Essays . New York: Columbia University

Press, 1969, pp. 69–90.


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it with a different kind of physics, one grounded in a mechanistic con-

ception of nature. For an Aristotelian physicist, natural philosophy is

ultimately grounded in the irreducible tendencies bodies have to

behave one way or another, as embodied in their substantial forms.Some bodies naturally fall, and others naturally rise; some are naturally

cold, and others are naturally hot; some are naturally dry, and others

are naturally wet. For the mechanist, though, the world is a machine,

all the way down. According to the mechanical philosophy, of which

Descartes was a founder, I would argue, everything in the physical world

must be explained in the way in which we explain machines, through

the size, shape, and motion of their parts. Descartes was not the only thinker of the period to hold such a view. Though there are some

interesting and important differences among them, differences that

Descartes himself emphasized in many cases, one must also include

here contemporary figures such as Galileo, Mersenne, Gassendi,

Hobbes, Roberval, and Beeckman, later Boyle, Locke, and many

others. Nor was the mechanical philosophy the only alternative to Aris-

totelianism; there were also alchemical, astrological, hermetic, Platonic,

and other alternatives in the mix. One must understand Descartes’philosophy as a part of this larger program to replace the Aristotelian

philosophy with a new and better alternative.

But there is a particular way in which Descartes approached the task

of replacing the Aristotelian philosophy with a mechanical philosophy.

Although Descartes was interested in what we would call mathematical

and scientific questions, it was important for him to ground his view of

the make-up of bodies and the laws that they observe in what he calleda metaphysics. In a celebrated passage from the preface to the French

edition of the Principia , Descartes writes that “all philosophy is like a

tree, whose roots are metaphysics, whose trunk is physics, and whose

branches, which grow from this trunk, are all of the other sciences,

namely medicine, mechanics, and morals.”2 In the philosophical liter-

ature, particularly that written by Anglo-American historians of philos-

ophy, almost all the attention has been to the metaphysical roots. I

thought that it would be very useful to turn my attention to the part of the tree above ground, the trunk and the branches which were, if any-

thing, more visible to Descartes’ contemporaries than the metaphysical

roots.

2 i ntro ducti on

2 AT IXB 14. See the note on abbreviations and translations for the conventions used in

citing Descartes’ writings.


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One of the fruits of this work was my book, Descartes’ Metaphysical

Physics .3 In this book, I tried to give a critical exposition of Descartes’

physical thought, and discuss the arguments and positions that Descartes

offered in his writings on physics, mainly Le Monde (1633) and the Prin- cipia Philosophiae (1644), paying special attention to the way in which they

are grounded in metaphysics. But, at the same time, I was also working

on some of the more traditional questions in Descartes’ thought, ques-

tions about knowledge, method, mind, and matter, exploring the way

in which understanding Descartes’ scientific thought might illuminate

those more familiar aspects of Descartes’ philosophy. Many of the essays

in this collection are part of this effort. In taking the approach I do inthese essays, I do not mean to argue that it is the only approach that one

can take, that the only way one can understand Descartes is through his

scientific writings. Descartes was a multifaceted character, and there are

a number of approaches that one can take to illuminate his thought. All

I mean to assert is that this is one of them.

I should also say something about the historiographical ideas that lie

behind these essays. The last twenty or thirty years have seen enormous

changes in the way in which the history of philosophy is written, at least in English. When I first began working in the field in the mid-1970s,

the dominant trend in Cartesian studies was to give careful attention to

Descartes’ arguments and positions, and scrutinize them in accordance

with the current philosophical standards and doctrines. What it also

meant, often enough, was a Cartesian philosophy pulled out of its intel-

lectual context, with any historical considerations explicitly marginal-

ized. I can remember in the late 1960s one of my undergraduate teachers wondering, in all seriousness, whether Descartes wrote before or after

Newton! Furthermore, the texts were almost always studied in transla-

tion, with no need to know either the original language texts or any of

the literature outside of English. Things have changed considerably

since then; the history of philosophy, at least in the early-modern period,

is more and more genuinely historical. It is getting less and less possible

to do history of philosophy in translation alone, with no attention to his-

torical context, and I am proud to have had some small part in thischange of standards. This historiographical theme is also reflected in the

essays collected here. For me, understanding Descartes historically

means first and foremost situating him in the context of the larger

introduction 3

3 Chicago: University of Chicago Press, 1992. It has recently appeared in French as La

physique métaphysique de Descartes , Paris: Presses Universitaires de France, 1999.


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intellectual trends. However, it should also involve the attempt to under-

stand Descartes as a living, breathing human being, who learns (and

forgets) things, whose views develop and change over time, even if he

himself is not always aware of that dimension of his thought.My historical temperament should not be taken to mean that I am

uninterested in philosophy, and that I am abandoning a genuinely

philosophical history of philosophy for a contextual history of ideas

or an intellectual biography. Like many philosophical historians of

philosophy, I believe in engaging historical figures, such as Descartes,

in critical discourse, and even in rationally reconstructing their

positions. However, as a historian of philosophy, I want as much aspossible to do so on their own terms. Insofar as my job is to illuminate

the thought of a Descartes or a Leibniz or a Locke, I would prefer to

do so by using terms and doctrines that they would find intelligible,

to debate with them in their own language. Again, I acknowledge

that this is not the only valid way of approaching the subject: It is

important for us now to understand why a Cartesian account of the

physical world is no longer acceptable, and to do this involves engag-

ing Descartes in a discussion with modern philosophy of science andeven modern physics. But unless we understand Descartes’ projects

on their own terms, in the terms in which they were conceived, we

cannot really understand what exactly his views really were, how they

really relate to current conceptions, and what their true philosophical

significance is.

It is for reasons like this that I want to downplay (or perhaps even

blur) the distinction between history of philosophy and history of ideas. As Bernard Williams characterizes the distinction in his classic book,

Descartes : The Project of Pure Enquiry ,4 “history of ideas is history before

it is philosophy, while with the history of philosophy it is the other way

round.” When dealing with an historical text, the history of ideas,

according to Williams, focuses on the question “what did it mean” for

its contemporaries, whereas the history of philosophy focuses on the

question of its philosophical content. Williams writes: “The history of

philosophy of course has to constitute its object, the work, in genuinely historical terms, yet there is a cut-off point, where authenticity is

replaced as the objective by the aim of articulating philosophical ideas.”

Williams casts his lot with history of philosophy understood in this

way, and offers a self-consciously twentieth-century reconstruction of

4 introduction

4 New York: Penguin Books, 1978. All the quotations are taken from pp. 9–10.


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Descartes’ thought. But can we really make the kind of separation that

Williams (and many, many others) postulate? I can certainly understand

those who want to ignore history, and attack philosophical questions

directly; this, in a way, is the Cartesian spirit. However, if one choosesto write about Descartes (or Spinoza, or Locke, or . . .), then, it seems,

this entails a kind of commitment to understand what they are trying

to say; a history of philosophy based on myths and partially understood

texts is neither good history nor good philosophy, substituting for

Descartes’ authentic thought a pale reflection of the contemporary

views of interest to us. If we are to learn philosophy from Descartes, as

opposed to using him as a mere foil for our contemporary views, then we must try to reach genuine understanding of what he thinks. And

genuinely understanding an historical figure requires significant his-

torical work, often going beyond the texts themselves and into the con-

temporary culture to understand their presuppositions. Similarly, one

cannot approach good history of ideas (in Williams’ sense) without

understanding the philosophy as philosophy, as arguments and dis-

tinctions and attempts at addressing systematically what are taken to be

important problems. I don’t think that one should have to choosebetween the one and the other, between philosophical interest and

historical sophistication. One needs both. Period.

Though the essays in this collection are all attempts at recovering a

genuinely historical Descartes, in reading them over again, I am struck

by how far scholarship has come in the last years. When I originally

wrote them, and when they were originally published, many of these

essays were then on the outer edge of what was acceptable in the history of philosophy; it is only through the kindness of editors who invited me

to contribute to collections or special issues of journals that many of

them found their way into print. But looking back at them now, they

seem, in a sense, rather old-fashioned. The essays are based on a careful

reading of the texts, all the texts, and not just the few generally read in

philosophy classes. Also, I try very hard to put those texts in the context

of other texts then in circulation, particularly late scholastic texts.

However, two main things are missing. Although there is a smatteringof names unfamiliar to historians of philosophy, there are not enough

of them. In part this defect is addressed in the Cambridge History of

Seventeenth-Century Philosophy ,5 which I co-edited with Michael Ayers.

There we made sure that less familiar names such as Sir Kenelm Digby,

introduction 5

5 Cambridge: Cambridge University Press, 1998.


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Henry More, Louis de La Forge, and many others were reintegrated in

the story. But what is missing even there is the social context. Ideas exist

in people, and people exist in societies. As a consequence, social factors

can sometimes play a nonnegligible role in philosophy. Although thisis a commonplace now in the history of science (indeed, probably over-

done), it is, I suspect, still a heresy in the history of philosophy. While

I was doing my best to be heretical in some of the essays published in

this volume, the social historical approach was a kind of heresy that I

hadn’t yet come to appreciate. It will be better represented in some

work currently in progress, a general study of the rise of the “new

philosophy” in Paris in the 1620s and beyond.It may be helpful to the reader to provide a brief guide to the con-

tents of the book, and point out some themes and connections that

might not be evident at first reading.

Part I of the book (“Historiographical Preliminaries”) is a general

historiographical essay, (1) “Does History Have a Future?” In this

essay, I treat the general question of how one ought to do the history

of philosophy, and why one ought to do it. I argue, most centrally

against Jonathan Bennett, but also against many who share his con-ception of the history of philosophy, that the history of philosophy

should be done in a historically responsible way, and that the only way

to recover the true philosophical significance of historical figures is to

understand them in their proper historical context. I further try to show

what the history of philosophy done in this way can contribute to the

enterprise of philosophy, how it can be used to challenge assumptions

that we take for granted by exhibiting philosophical programs withperspectives very different from ours. This essay serves to present

the methodology that I follow in the remainder of the essays in the

collection.

Part II of the collection (“Method, Order and Certainty”) is con-

cerned with methodological and epistemological issues in Descartes’

philosophy. In (2) “Descartes and Method in 1637,” I treat the method

as articulated in Descartes’ Rules for the Direction of the Mind (1620–1628

(?)) and the Discourse on the Method (1637). It is generally assumed that the method that Descartes articulates in those earlier works follows

him throughout his career. In opposition to that, I argue that in an

important sense, the official method is abandoned in Descartes’ later

writings, both scientific and philosophical. In the following two essays,

(3) “A Point of Order: Analysis, Synthesis, and Descartes’s Principles ”

6 introduction


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(written jointly with Lesley Cohen) and (4) “J. B. Morin and the Second

Objections ,” I treat the question of geometrical method in Descartes’

writings. There is a standard reading of Descartes in accordance with

which the Meditations (1637) are written in the analytic style, suppos-edly following the method of discovery of the Rules and the Discourse ,

whereas the more scientifically oriented Principles of Philosophy (1644)

was written in the synthetic style characteristic of Euclidean geometry.

This distinction has shaped a number of readings of Descartes’ philos-

ophy, including most visibly the influential reading of Martial Guer-

oult.6 In “A Point of Order” I argue against this dogma of Cartesian

scholarship and suggest how to understand the different styles of thesetwo central works in Descartes’ corpus. In “J. B. Morin and the Second

Objections ” I extend the argument by showing that one of the texts that

supposedly grounds this interpretation, the end of the Second Replies to

the Meditations , was originally written not to endorse the synthetic

method in any way, but as a reaction against another philosopher (and

well-known Aristotelian, anti-Copernican, and astrologer of his day),

Jean-Baptiste Morin, who wrote a short tract on the existence of God

in the style of a Euclidean geometry text, a tract from which Descartesclearly wanted to dissociate himself. The last two essays in this part

concern Descartes’ actual method of conducting experimental

inquiries in his earlier and later works. In (5) “Descartes and Experi-

ment in the Discourse and Essays ” I show how, Descartes’ method

from the Rules and the Discourse was used in the practice of experi-

mental science by examining his analysis of the rainbow as given in the

Meteors , published with the Discourse in 1637. In that essay, I try to show how, for Descartes in this period, experiment is fully consistent with

certainty. In (6) “Descartes on Knowledge and Certainty,” I show how

the problems of experimental philosophy ultimately move Descartes

to abandon the claim that he can have certain knowledge of the

microstructure of matter, something that I think he had earlier believed

he could have.

Part III of the collection (“Mind, Body, and the Laws of Nature”) is

concerned with a number of central metaphysical and scientific ques-tions in Descartes’ philosophy. In (7) “Mind, Body, and the Laws of

introduction 7

6 See Martial Gueroult, Descartes’ Philosophy Interpreted According to the Order of Reasons , trans.

Roger Ariew. (2 vols.) Minneapolis: University of Minnesota Press, 1984; and Nouvelles

réflexions sur la preuve ontologique. Paris: Vrin, 1955.


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Nature in Descartes and Leibniz,” I discuss the relation between

voluntary activity and the laws of nature. It has been a standard view of

Descartes that he had wanted to make all the physical behavior of the

human being consistent with his law of the conservation of quantity of motion. On that reading, Descartes is supposed to have held that the

human will can change the direction of the motion of a body, but not

its speed. Since Descartes’ conservation law governs only speed and not

direction, it was thought that this account allowed Descartes to render

human voluntary activity consistent with his conservation law. However,

Leibniz showed that Descartes’ conservation law is incorrect, and that

the correct conservation laws constrain direction as much as they dospeed. And so, Leibniz argued, that ploy won’t work. By carefully exam-

ining Descartes’ conception of the laws of nature and how they derive

from God, I argue that Descartes never intended human beings to be

governed by his laws of nature. I also show how Leibniz’s metaphysics

differs profoundly from Descartes’ in this regard, and why for him, the

human being cannot stand outside of nature, as it can for Descartes.

The following essay, (8) “Understanding Interaction: What Descartes

Should Have Told Elisabeth,” also concerns mind and body inDescartes. It argues that Descartes’ famous letters to Elisabeth in 1643,

explaining mind-body and body-body interaction, are importantly mis-

leading. In those letters, Descartes claims that mind-body interaction

and body-body interaction are each understood through their own sep-

arate primitive notions. This, I claim, is inconsistent with some of

Descartes’ most basic commitments elsewhere. Rather, I argue, body-

body interaction, the interaction between inanimate physical objects,must be understood ultimately through God, whose activity determines

the laws of motion. The activity of God, in turn, must be understood

through our own experience of how we act on our own bodies. In this

way, mind-body interaction is the ultimate model in terms of which we

understand all physical interaction for Descartes. The analysis of the

physical interaction among bodies is continued in the next piece, (9)

“How God Causes Motion: Descartes, Divine Sustenance, and Occa-

sionalism,” where I discuss how the dependence of the laws of natureon God gives rise to accusations of occasionalism in Descartes, and

explicit arguments for occasionalism in some of his followers. I argue

that the way in which Descartes conceives of divine activity leads him

to reject a full occasionalism, where God is the only genuine causal

agent. However, differences in the way some of his followers conceive

of divine activity lead them in another direction, to the occasionalism

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characteristic of the later Cartesian tradition. In the following essay,

(10) “Descartes and Occasionalism,” the question of Descartes’ occa-

sionalism is examined in a more general way, where it is argued that

contrary to much of the critical literature, Descartes was not a genuineoccasionalist. The last two essays in this section, (11) “Semel in vita : The

Scientific Background to Descartes’ Meditations ” and (12) “Forms and

Qualities in the Sixth Replies ” both deal more directly with the relation

between Descartes’ metaphysics and his physics. “Semel in vita ” gives a

general overview of the way in which Descartes’ metaphysics and epis-

temology undermine Aristotelian science and ground the new physics

that he is presenting in his works. “Forms and Qualities” discusses morespecifically the issue of Descartes’ rejection of Aristotelian forms and

qualities, particularly as it is treated in a crucial passage at the end of

the Sixth Replies .

In Part IV of the collection (“Larger Visions”), I include two essays

that give larger views of Descartes’ philosophy. In (13) “Descartes, or

the Cultivation of the Intellect,” I present a view of Descartes’ concep-

tion of the educated person, and how his conception of the human

being and the natural world led to a revolutionary conception ofeducation, rejecting the authority of the book and the teacher for

the authority of the intellect. Finally, in (14) “Experiment, Community,

and the Constitution of Nature in the Seventeenth Century,” I put

Descartes’ epistemology in the context of larger movements in seven-

teenth-century thought, and show how Descartes’ radically individual-

istic epistemology eventually gave way to a more social conception of

knowledge and scientific inquiry, as institutions such as the RoyalSociety of London and the Académie des Sciences in Paris entered the

scene, and redefined the scientific world.

The careful reader may have noticed an oddity in the subtitle of this

collection, “Reading Cartesian Philosophy through Cartesian Science.”

Strictly speaking, this title makes little sense for the seventeenth

century. At that time, neither philosophy nor science as we now know

them could properly be said to exist as distinct domains of knowledge: What we call philosophy and what we call science were part of a single

domain of inquiry, which went under the rubric of philosophy. But

within Descartes’ thought there certainly was a distinction between the

foundational disciplines of philosophy, what he called “first philosophy”

or sometimes “metaphysics,” and natural philosophy, between the roots

of his tree of philosophy and the trunk. It is this distinction that I have

in t r odu c t io n 9


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in mind when I am talking about reading the philosophy through the

science. What I am attempting to do is put some of the Cartesian

metaphysical, epistemological, and methodological doctrines on which

philosophers have concentrated in recent years into the perspective of Descartes’ larger system.

10 i n t r o d u c t i o n


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PART I

HISTORIOGRAPHICAL PRELIMINARIES


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1

DOES HISTORY HAVE A FUTURE?

Some Reflections on Bennett and Doing Philosophy Historically

The history of philosophy seems to play a very significant role in the

actual practice of philosophy; historical figures come up again and

again in the courses we had to take, both as undergraduates and as

graduate students, and historical figures continue to come up again and

again in the papers we read, the courses we teach, the conferences weattend. Philosophy seems to be a subject that is obsessed with its past,

but it is more than just an obsession. Most of us would agree that under-

standing the history of philosophy is somehow important to doing phi-

losophy, that we are better philosophers for knowing the history of our

subject. I think that this is true. As philosophers, we have an obligation

to ourselves to reflect on this fact: why is history important to our enter-

prise, and how is history important to our enterprise?This is what I would like to do in this short essay, make some obser-

vations about the ways in which history of philosophy can and does

influence the practice of philosophy. I shall begin by discussing the view

of history found in Jonathan Bennett’s recent and already enormously

influential book, A Study of Spinoza’s Ethics . I have chosen to talk about

that book in good part because it is, I think, the best representative of

a certain genre of writing in the history of philosophy; Bennett nicely

articulates a view of the history of philosophy that is widespread among writers on the subject, particularly those writing in English. Bennett’s

view, widely shared, is that history is important because studying his-

torical figures can teach us philosophy; in the history of philosophy we

have a storehouse of arguments and positions worth taking seriously as

philosophy, worth discussing and debating in the same way the work

of a very good contemporary philosopher is worth discussing and

13


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debating. I shall not really criticize Bennett’s view of the matter. There

is a sense in which he and the multitude of other philosophers and his-

torians of philosophy who share his view are absolutely correct. But, I

shall argue, Bennett makes use of only a portion of the riches that history has to offer. In the second part of this essay I shall try to sketch

and illustrate a somewhat different conception of the use of history in

philosophy that complements the conception Bennett offers.

History as Storehouse

I would like to begin my discussion by outlining what I take to be

Jonathan Bennett’s attitude toward history in his recent book, A Study

of Spinoza’s Ethics . My interest in the book will be largely metaphilo-

sophical (or, perhaps, metahistorical); though I have some disagree-

ments with Bennett on matters of substance, I shall do my best not do

drag them in here and muddy the waters.

Early in the book, Bennett gives the reader ample indication of the

nature of his interest in Spinoza. “I am not writing biography,” he notes.

“I want to understand the pages of the Ethics in a way that will let melearn philosophy from them.”1 A bit later in the book, Bennett indi-

cates that his interest is “not with Spinoza’s mental biography but with

getting his help in discovering philosophical truth.”2 At the end of the

book Bennett writes:

The courtly deference which pretends that Spinoza is always or usually right,

under some rescuing interpretation, is one thing; it is quite another to look

to him, as I have throughout this book, as a teacher, one who can help us tosee things which we might not have seen for ourselves. That is showing him

a deeper respect, but also holding him to a more demanding standard.3

Bennett’s interest here is clear: it is finding philosophical truth and

avoiding philosophical falsehood that he is after, and the study of

Spinoza is supposed to help us in this search. What he says about

Spinoza presumably holds more generally for the study of other figures

in the history of philosophy. So conceived, the history of philosophy isa kind of storehouse of positions and arguments, positions and argu-

ments that we can use as guides or inspirations to the positions we

should take, or illustrations of dead ends that we should avoid.

14 historiographical preliminaries

1 Jonathan Bennett, A Study of Spinoza’s Ethics (Indianapolis, Ind.: Hackett Publishing

Company, 1984), p. 15.

2 Ibid., p. 35. 3 Ibid., p. 372.


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This last provision is important. The point is not that Spinoza (or any

other historical figure) will simply hand us philosophical truth on a

platter, arguments or positions that we can immediately adopt without

change. Bennett’s Spinoza often makes mistakes, and bad ones; hardly an argument in the Ethics can stand without some correction. Yet we can

learn from Spinoza even when he is wrong (or, at least we usually can;

Bennett seems unsure about whether anything can be learned from the

mistakes Spinoza makes when discussing the eternity of the mind).4

Bennett writes:

I do say that Spinoza’s total naturalistic program fails at both ends and in the

middle; as though he undertook to build a sturdy mansion all out of wood,and achieved only a rickety shack using bricks, as well as wood. But his

attempt was a work of genius; and a thorough, candid study of it can be won-

derfully instructive. The failures have at least as much to teach as the suc-

cesses, if one attends not only to where Spinoza fails but why .5

Bennett completes the thought a few pages later:

I spoke of how much we can learn from Spinoza’s successes and, especially,

his failures. It is his minimalism that makes his work so instructive. If you set

a mechanical genius to build an automobile engine out of a Meccano set,

you won’t get a working engine from him, but as you watch him fail you will

learn a lot about automobile engines.6

(In giving these quotations I don’t mean to imply that they are trans-

parently intelligible or true on their face, but I would like to postpone

those questions for the moment.)

What does the history of philosophy look like from Bennett’s point of view? We begin by trying to reconstruct the arguments the philosopher

we are studying gave, trying to follow the train of thought he followed.

But our ultimate goal is philosophical truth, and it is with that in mind

that we must approach our reconstruction; we must carefully examine

the truth of the premises, the validity of the inferential steps, and with a

cold and unsentimental eye, judge the truth or falsity of the conclusion

and the adequacy of the means by which the conclusion was reached. If

appropriate, we might make some attempt to patch up the argument,

adding new premises, substituting better premises for worse, trying a new

path to the conclusion in question, or whatever. This is, I think, a fair

representation of what Bennett is doing in the Spinoza book.

does history have a future? 15

4 Ibid., pp. 372, 357. 5 Ibid., p. 38. 6 Ibid., p. 41.


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All of this is interesting and, in an important sense, valuable activity.

But if we are to follow Bennett and hold that the history of philosophy

is valuable primarily insofar as it helps us to find philosophical truth,

in some more or less direct sense, then there are certain consequences we must accept.

First of all, if we insist on philosophical truth as the only motivation

for studying history, then a great deal of the history of philosophy may

turn out to be marginal to the philosopher. Bennett would agree that

few historical figures have any large store of doctrines or arguments

that we would now consider live candidates for truth or even approxi-

mate truth. There are those who study Aristotle or Saint Thomas, Kant or Marx, because they think that at least some of what they wrote is

close to being true, and because they believe that attention to their writ-

ings can help lead us directly to insights we would not otherwise have.

But how many study Descartes or Leibniz or Spinoza for this reason?

The noble attempts of the past, one might argue, are instructive in their

failures . But while failures can be instructive, a few can go a long way.

The student architect can learn to fit the building to the available

materials and know the strengths and weaknesses of both from thebuilding that collapsed. But one learns to design successful buildings

by studying successful buildings, not just failures. Having had a deprived

childhood, I’m not sure I know exactly what a Meccano set is, but if it

is what I think it is, I doubt that I could learn much about automobile

engines by watching someone try to build one from a Meccano set, no

matter how talented one might be. Similarly, the philosopher must

learn to recognize a bad argument and must be trained to avoid themistakes people make. This is only a small portion of one’s philosoph-

ical education, which, I think, should focus on positions and arguments

that people think are live candidates for the truth, at least insofar as

one is being trained to seek philosophical truth. Bennett may overesti-

mate what we can learn directly from failed arguments and programs.

Insofar as the great majority of historical arguments, positions, and pro-

grams are failures when judged against the high standard of philo-

sophical truth (as we see it), the study of the history of philosophy may have less to contribute to philosophy than Bennett seems to think, and

less than we historians would like.

There is another feature of Bennett’s position worth drawing out.

Bennett’s position has the danger of distorting the history of philosophy.

First of all, insofar as we regard history of philosophy as contributing to

the discovery of philosophical truth, we are led to emphasize those por-

tions of a philosopher’s work that speak to our interests, that address our



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conception of where philosophical truth is to be found, leaving otheraspects of the work aside, thereby mutilating what may be a unified andsystematic point of view. Bennett has not done any such thing to Spinoza,

but one can call to mind the numerous commentaries on Descartes andanthologies of his writing that barely mention his work in mathematics,physics, or biology; the accounts of Pascal that focus on the wager argu-ment without indicating its larger context; books like Anthony Kenny’slittle book Aquinas , in the Past Masters series, or John Mackie’s Problems

from Locke , which quite self-consciously use standards of contemporary relevance to choose what to discuss and what to ignore. In each case, the

focus on philosophical truth distorts our historical understanding of thefigure and his position. But there is another way in which historical dis-tortions may enter. If our interest is philosophical truth, then the point of the historical enterprise is to capture whatever philosophical truth orinteresting philosophical falsehood there may be in some philosopher’s

writings. What this has often meant in practice is what has been dubbedrational reconstruction , taking the argument or position as given andmaking sense of it in terms that make sense of it to our philosophical

sensibilities, whether or not the reformulation captures anything thephilosopher himself would have acknowledged. Examples of thisinclude Bernard Williams’s reconstruction of the argument of Descartes’Meditations using modern epistemological concepts, or Benson Mates’sreconstruction of Leibniz’s doctrine of possible worlds using contem-porary modal logic. Bennett is tempted in this direction as well. In apassage, part of which we have already quoted, he writes:

I want to understand the pages of the Ethics in a way that will let me learnphilosophy from them. For that, I need to consider what Spinoza had in

mind, for readings of the text which are faithful to his intentions are likely

to teach me more than ones which are not – or so I believe, as I think him

to be a great philosopher. And one can be helped to discover his intentions

by knowing what he had been reading, whose problems he had been chal-

lenged by, and so on. But this delving into backgrounds is subject to a law of

diminishing returns: while some fact about Maimonides or Averroes might

provide the key to an obscure passage in Spinoza, we are more likely to get his text straight by wrestling with it directly, given just a fair grasp of his

immediate background. I am sure to make mistakes because of my inatten-

tion to Spinoza’s philosophical ancestry; but I will pay that price for the ben-

efits which accrue from putting most of one’s energies into philosophically

interrogating Spinoza’s own text.7


7 Ibid., pp. 15–16.


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Indeed, many benefits come from directly interrogating a historical

text, leaving aside nice worries about historical context, but there is a

danger of misunderstanding. (In Bennett’s Spinoza book this comes

out most clearly in his discussion of space and his attribution of a “fieldmetaphysic” to Spinoza in chapter 4, a lovely philosophical position,

but one that I do not think occurred to Spinoza.)

This may sound like a criticism of the approach Bennett takes to

history, but I assure him, it is not. If our only goal is philosophical truth,

then history of philosophy may turn out to be marginal, if not alto-

gether expendable; If our goal is simply philosophical truth, we must

face up to the facts in an unsentimental way. And, if our goal is philo-sophical truth, then historical veracity can have only an instrumental

value at best; it is of value only insofar as it helps us attain our princi-

pal goal. The point of interpretation, on this view, is to make the phi-

losophy breathe, to make it available to us, and historical veracity is

important only insofar as it serves this end.

In calling for us to focus on the truth and falsity of Spinoza’s claims,

the adequacy and inadequacies of his arguments, Bennett is implicitly

contrasting the approach that he takes with other more disinterestedly historical and, in one sense, less philosophical approaches that one

might take to the material. In one place Bennett contrasts his approach

with that of “intellectual biography,” with “mental biography” in

another, and with that “which pretends that Spinoza is always or usually

right, under some rescuing interpretation” in a third passage.8 Now, it

seems to me that the disinterested historian shouldn’t always assume

that Spinoza is right . But insofar as we agree with Bennett that Spinoza was “a great philosopher,” we should at very least subscribe to the

working hypothesis that what Spinoza is up to is sensible , the sort of thing

that a smart person might believe in a particular historical context,

given what he had learned, what others around him believed, the

assumptions taken for granted, and so on. (This is just a special case of

what has been called the principle of charity or, in variant, the princi-

ple of humanity in the theory of interpretation in the philosophy of

language.) This is not to say that we should not expect to find lapses of reasoning and judgment, even when the whole context is open to us,

or that this kind of historical inquiry will clear up all our puzzlements.

It is important to remember that Spinoza, for example, was a puzzle to

his contemporaries as well, and they had more access to his context


8 Ibid., pp. 15, 35, 372.


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than any of us can ever hope to have. In its way, this kind of rationality

is no less demanding a standard to hold Spinoza to than philosophical

truth is.

Unlike philosophical truth, which judges Spinoza by what is true, orby what we have come to think is true, this standard is internal . The

alternative to the sort of history Bennett advocates is an historical recon-

struction of Spinoza’s views, the attempt to understand Spinoza’s posi-

tions and arguments in terms that he or a well-informed contemporary

of his may have understood. It involves coming to understand what

Spinoza or a contemporary of his would have considered unproblem-

atic background beliefs, what they would have had trouble with, and inthe light of that and other similar contexts, coming to understand what

Spinoza’s conception of his project was, how he thought he had estab-

lished the conclusions he had reached, and what he thought was impor-

tant about those conclusions, all under the assumption that, by and

large, Spinoza’s project is the work of a smart person working within a

particular historical context. This sort of investigation is not biography

of any sort, neither intellectual nor mental; it is, quite simply, the history

of philosophical ideas.In practice, the kind of history I was sketching may come out looking

very little different from the history Bennett prefers. As Bennett has

pointed out, if it is the lessons of history for philosophical truth that

interest us, then the lessons are likely to be more interesting the closer

we come to a genuine representation of Spinoza’s (or whoever’s)

thought. The only conspicuous difference may be the relative lack of

judgments of truth and falsity in the sort of disinterested history Ipropose. If our interest is in historical reconstruction, the question of

the ultimate truth or falsity of the doctrines is simply not at issue; the

only thing that is important is whether or not our account has made

the beliefs intelligible. Sometimes this will call for a judgment that on

his own terms , some premise or inference a philosopher uses may not be

available to him, properly speaking. If we are interested in historical

reconstruction, then, for example, the falsity of a premise then univer-

sally accepted is not a relevant part of the story.Bennett would certainly have to agree that there is a real project

here, whether or not he himself is interested in carrying it out. I think

that he would also have to agree that there is no reason why one must

choose one conception of the history of philosophy over the other.

While in practice a single scholar may find it difficult to pull off both

sorts of history at the same time, within the confines of a single essay



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or book, they are not competing programs in the sense in which, say,

deontological programs for ethics compete with teleological programs.

One can find the history of philosophy richer for having both

approaches represented in the literature, one can find both interestingand never be put into the position of having to choose one over the

other. In this sense the two approaches to history of philosophy are

complementary rather than competing.

A question remains, a central question. On Bennett’s view, the

history of philosophy is important to philosophy in an obvious way; on

his conception, history of philosophy actually contributes to the

unearthing of philosophical truths. Now, as I noted, the sort of disin-terested historical reconstruction I have sketched can contribute

to Bennett’s enterprise, but taken by itself, does it have any philosoph-

ical interest at all? Leaving aside the question of the philosophical

truth it may help to uncover, is the purely historical study of philo-

sophical ideas of more than antiquarian interest? Is there any reason

for philosophers qua philosophers to take an interest in such dis-

interested history?

In Defense of Disinterested History

In arguing for the philosophical significance of disinterested history, I

would like to proceed historically and begin with a consideration of the

views of a philosopher whose opinion on the matter is in many ways

attractive to me. The philosopher I have in mind here is Descartes. As

Bennett proposes we learn from Spinoza, I propose that there is much we can learn from Descartes.

Descartes may seem at first glance an odd character to turn to in this

connection. Descartes was conspicuously unsympathetic to the study of

books, old or new. In the Discours , Descartes wrote:

[A]s soon as I was old enough to emerge from the control of my teachers, I

entirely abandoned the study of letters. Resolving to seek no knowledge other

than that which could be found in myself or else in the great book of the world, I spent the rest of my youth in traveling. . . . For it seemed to me that

much more truth could be found in the reasoning which a man makes con-

cerning matters that concern him than in those which some scholar makes

in his study about speculative matters. For the consequences of the former

will soon punish the man if he judges wrongly, whereas the latter have no

practical consequences and no importance for the scholar except that

perhaps the further they are from common sense the more pride he will take



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in them, since he will have had to use so much more skill and ingenuity in

trying to render them plausible.9

This attitude also comes out nicely in a letter from 1638. Unfortunately,

the recipient of the letter is unknown, as is the book Descartes is com-

menting on in the letter, but his point is clear:

[The author’s] plan of collecting into a single book all that is useful in every

other book would be a very good one if it were practicable; but I think that

it is not. It is often very difficult to judge accurately what others have written,

and to draw the good out of them without taking the bad too. Moreover, the

particular truths which are scattered in books are so detached and so inde-

pendent of each other, that I think one would need more talent and energy to assemble them into a well-proportioned and ordered collection . . . than

to make up such a collection out of one’s own discoveries. I do not mean

that one should neglect other people’s discoveries when one encounters

useful ones; but I do not think one should spend the greater part of one’s

time in collecting them. If a man were capable of finding the foundation of

the sciences, he would be wrong to waste his life in finding scraps of knowl-

edge hidden in the corners of libraries; and if he were no good for anything

else but that, he would not be capable of choosing and ordering what hefound.10

Descartes does not mince words here. If it is truth we are after, books

will not help us to find it. He does not seem to think that we can learn

much from other people’s mistakes, unlike Bennett; mistakes just

engender other mistakes. The truths we find in books are so rare and

so scattered that anyone who has the ability to recognize them and seek

them out would be better off simply looking for them on his own,directly, without the help of these paper-and-ink teachers. If it is philo-

sophical truth you are after, Descartes tells Bennett (and anyone else

who will listen), then don’t look to the philosophers of the past. (It is

somewhat disquieting to the historian when one of his or her subjects

talks back in such a rude way.)

Descartes, in general, has little truck with scholarship, with the study

of the past, but Descartes was not altogether dismissive of history.

Though he thought it inappropriate to look for philosophical truth in

history, he did not think that reading the authors of the past is altogether

without value. In the Discours he wrote:


9 Descartes, Discours de la methode , I, AT VI 9–10; CSM I 115.

10 AT II 346–47; CSMK 119.


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I knew . . . that reading good books is like having a conversation with the most

distinguished men of past ages – indeed, a rehearsed conversation in which

these authors reveal to us only the best of their thoughts.11

This conversation is valuable to us for an interesting reason. According

to Descartes:

[C]onversing with those of past centuries is much the same as traveling. It is

good to know something of the customs of various peoples, so that we may

judge our own more soundly and not think that everything contrary to our

own ways is irrational, as those who have seen nothing of the world ordinar-

ily do.12

Through such experience in books and in the world Descartes claims

that he learned that there are “many things which, although seeming

very extravagant and ridiculous to us, are nevertheless commonly

accepted and approved in other great nations; and so I learned not to

believe too firmly anything of which I had been persuaded only by

example and custom.”13

The idea is an interesting one. We can learn from the past in some-

thing of the same way we can learn from travel. By traveling we can get a certain kind of perspective on our lives and the way we lead them, the

things we do and the things we believe. We go to other countries, learn

their languages, observe their customs, eat their foods (or, at least,

observe the kinds of foods they eat), discuss their beliefs about the

world. This, Descartes thinks, can give us a certain perspective on our

own lives. It can, among other things, free us of the belief that the way

we see things is the way things have to be, that X is fit for human con-sumption but Y is not, that weeks must have seven days, that children

must be raised by their own parents, etc. Descartes’ point is not rela-

tivistic here; he would be among the last to say that anything goes. Even

though we observe others eating a certain food we do not, we may still

shun it and continue to hold the belief that it is unhealthy or improper

for us to eat. Seeing what others do may at least get us to raise the ques-

tion for ourselves why we have the beliefs and customs we do and,

perhaps, lead us to see what is arbitrary and what is well grounded inour beliefs and behavior.

A similar case can be made with respect to the study of the past in

general, and the study of past philosophy in particular, Descartes sug-


11 Discours I, AT VI 5; CSM I 113. 12 Discours I, AT VI 6; CSM I 113–14.

13 Discours I, AT VI 10; CSM I 115–16.


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gests. Many of the philosophical beliefs we now take for granted are not

shared by figures in the past. By studying the past, taking the past seri-

ously, we are led to reflect on our beliefs, in just the same way as we are

led by travel to reflect upon our customs. Such reflection need not leadto a change in our beliefs. The fact that some past geographers thought

the earth flat, or past physicists thought that there is such a thing as

elemental fire that by its nature rises, these historical observations

should not move us to give up our present conceptions of geography

or combustion. Reflection on some of the things people have believed

should at least cause us to ask ourselves why we believe the things we

do, and whether our grounds are sufficient to support the explicit orimplicit beliefs we have and assumptions we make.

Is such reflection important for us as philosophers? It does not

directly contribute to the discovery of philosophical truth in the way in

which discovering a good argument (or an interesting false one) in the

work of a historical figure perhaps might, in the way in which Bennett

conceives of history contributing to the practice of philosophy. The sort

of contribution Descartes saw was of a different, and more subtle,

though no less important kind. Historical investigation conceived inthis alternative way gives us a kind of perspective on the beliefs we have

and the assumptions we make. It helps us sort the good from the bad,

the arbitrary from the well grounded, insofar as it challenges us to

reflect on why we believe what we do. While it may not help lead us

directly to new arguments and new philosophical truths, it leads us

directly to something just as valuable: philosophical questions .

All of this is very abstract and cries out for some concrete examples,specific assumptions and beliefs we make that are illuminated by such

historical reflection. Before I present such an example, I would like to

continue a bit longer in this abstract vein.

Descartes has suggested a philosophical use for the history of phi-

losophy different from the one Bennett suggests; the suggestion, as I

have developed it, is that the history of philosophy can be important

not because it leads to philosophical truths , but because it leads to philo-

sophical questions . But what sort of history is relevant here? To learnfrom history in the way Descartes suggests we can involves trying to

understand historical figures on their own terms . If I travel to Tokyo or

Nairobi, look for what is familiar to me in the alien setting, and seek it

out, I may acquire a nice camera cheaply, or learn one way not to make

a pizza. I may indeed have a lovely vacation, but I will not learn what

I might. Similarly, if what I am looking for in history is a guide to



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philosophical truth, if I look for things recognizable to me as interest-

ing philosophical problems and promising (if possibly flawed) philo-

sophical arguments, as Bennett seems to suggest we should, then I may

miss features of philosophy as it has been that might raise interestingquestions about philosophy as it is. To learn from history in the way

Descartes suggests, we should – we must, I think – undertake the kind

of disinterested historical investigation I suggested earlier as an alter-

native to the sort to which Bennett’s views lead him. If it is an histori-

cal perspective on our beliefs and assumptions we are interested in, then

the truth or the falsity of past views is simply irrelevant . It matters not at

all whether Descartes’ or Aristotle’s or Kant’s views are true or false forthis use of history. What is important is that we understand what their

views were, and that we understand how it is that smart people could

have regarded them as true. It is not their truth, much less their falsity,

that causes us to reflect on our own beliefs; it is the fact that smart

people took seriously views often very different from ours that is

important here.

This, I think, answers the question posed at the end of the last

section. The sort of disinterested historical reconstruction I proposedas a complement to Bennett’s philosophically informed investigation of

the history of philosophy is philosophically significant, a worthwhile

activity for philosophers to engage in, though for a reason somewhat

different from what Bennett suggests for his program. Bennett’s history

seeks philosophical truth, answers to philosophical questions; mine

seeks the questions themselves .

Raising Questions: Science and Philosophy

I have been sketching out a way of doing philosophy historically, using

a disinterested historical reconstruction of past thought as a way of

raising important philosophical questions that might otherwise escape

our notice. A brief example illustrates the approach I have been

advocating.

Bennett makes an interesting statement in the course of his com-mentary on Spinoza. He writes: “Much of the Ethics is philosophical

rather than scientific, i.e., is answerable to conceptual analysis rather

than to empirical observation”14 The claim is not central to Bennett’s

reading of Spinoza, and in raising questions about it I don’t mean to


14 Bennett, Spinoza , p. 24.


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cast doubt on Bennett’s larger interpretation (though I do think that on at least one occasion it does lead him a bit astray). The quotationappeals to a certain widely held conception of philosophy: that it is an

activity pretty largely distinct from scientific activity, and that philoso-phy makes use of conceptual analysis, whereas science makes use of observation and experience. This conception of philosophy and its rela-tion to science is worth some historical examination.

We might begin by noting that in Spinoza’s day, things were not soneatly partitioned. It is now generally recognized that the words “phi-losophy” and “science” didn’t have distinct and separate meanings in

the seventeenth century. Whereas “philosophy” was sometimes usednarrowly, in perhaps something of the way we use it now,15 it was alsoused more broadly to include knowledge in general, including what wenow call science, as in the title to Descartes’ Principia Philosophiae , three-fourths of which is scientific by our standards. Similarly, whereas“science” was sometimes used as we do now,16 it often took on a meaningderived from its Latin origin, scientia , knowledge. This, of course, is only a matter of terminology. The important question is not what things were

called, but whether Spinoza and his contemporaries drew an interest-ing distinction between what we call philosophy and what we areinclined to call science, between a certain collection of foundationalquestions, investigated through argument and conceptual analysis, anda different set of questions about the natural world, investigatedthrough observation and experience.

Here, I think we can say that while we can certainly find different

questions studied by different thinkers using different modes of inves-tigation, there is no radical distinction between what we call philo-sophical and what we call scientific.

It is quite widely known that arguments that are in general termsphilosophical play a major role in seventeenth-century science. A niceexample is the derivation Descartes gave for his laws of motion.Descartes started from two main premises. The first was an analysis of the “nature of time,” which, Descartes claims, is “such that its parts are

not mutually dependent,” and from which he argued that God isrequired to keep everything in existence at every moment.17 The


15 See, e.g., Discours I, AT VI 6, 8–9; CSM I 113, 114–15.16 See, e.g., the preface to the French translation of the Principia Philosophiae , AT IXB 14,

CSM I 186.17 Principia I 21, AT VIIIA 13; CSM I 200.


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second premise was that God is immutable by his nature and operates

“in a manner that is always constant and immutable.”18 From these

premises Descartes argued that a constant quantity of motion is main-

tained in the world, and that bodies in uniform rectilinear motion willtend to remain in uniform rectilinear motion.19 These conclusions, con-

clusions that spring from Descartes’ metaphysical foundations, were

enormously influential on later seventeenth-century physicists. Though

not altogether correct in detail, Descartes’ conclusions constituted the

first published statement of a conservation principle and the first clear

version of what Newton was later to call the principle of inertia. When

Newton presented his version of these laws in his Principia almostfifty years later, the metaphysical argument was gone. But it wasn’t

dead. Leibniz, Newton’s great and greatly maligned contemporary,

a physicist and mathematician whose only clear better was Newton

himself, made free use of metaphysical arguments in his physics. Like

Descartes, Leibniz chose to derive the laws of motion from God, though

in a different way: from God the creator of the best (and so, most

orderly) of all possible worlds, not God the moment-by-moment

sustainer of all. God, Leibniz reasoned, would want to create the worldin such a way that whatever power, whatever ability there is to do work

in a complete cause, must be found intact in its full effect. Using this

as his main premise, Leibniz established two of the main principles of

classical mechanics, the law of conservation of what we call kinetic

energy (mv 2, vis viva ), and the conservation of what we call momentum

(mv).20

These arguments establish what we would call scientific conclusionsby way of what we would call philosophical premises. There are also

instances in which what we would call (and Bennett has called) con-

ceptual analysis taken more narrowly is used in the service of science.

What I have in mind is Descartes’ celebrated arguments for the identi-

fication of space and body, and his conclusion that there is no empty

space, no vacuum. In one representative version, noted by Spinoza in

his Principles of Descartes’ Philosophy , quoted and discussed by Bennett in

his commentary, the claim reads:


18 Principia II 36, AT VIIIA 61; CSM I 240.

19 Principia II 36–39, AT VIIIA 61–65; CSM I 240–42.

20 For an account of Leibniz’s work here, see, e.g., Martial Gueroult, Leibniz: dynamique et

metaphysique (Paris: Aubier-Montaigne, 1967), chapter 3.


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Space and body do not really differ [because] body and extension do not

really differ, and space and extension do not really differ. It involves a

contradiction that there should be a vacuum [i.e.] extension without bodily

substance.21

Bennett claims that this position is a purely philosophical one, and that

neither Descartes nor, following him, Spinoza should confuse this with

doing science. He writes: “[W]hen he [Descartes] says that there is no

vacuum, he is not predicting what you will find if you ransack the phys-

ical universe. His point is a conceptual one.”22 Bennett furthermore

regrets “that he words this possible philosophical truth so that it sounds

like a scientific falsehood” and goes on to chastise Descartes andSpinoza for their occasional lapses into thinking that this philosophi-

cal argument has empirical consequences for physics.23 Bennett is too

charitable here, and in his charity, he misses the point of the argument,

both in Descartes and in Spinoza. Descartes’ point was precisely to estab-

lish that there is no vacuum in the physical world, and I know of no

reason to believe that Spinoza read the argument any differently.

Whether or not there is a philosophical truth in the claim, it was what

we have come to recognize as a scientific falsehood that interested

Descartes and his contemporaries; the denial of a vacuum not only

in philosophy but also in rerum natura was an important feature of

Cartesian physics, one that grounds Cartesian cosmology, the vortex

theory of planetary motion.24

The examples so far are of cases in which philosophical argument,

conceptual analysis, leads to what we would consider scientific conclu-


21 C. Gebhardt, ed., Spinoza Opera (Heidelberg: Carl Winter, 1925), 1:187–88, as para-

phrased in Bennett, Spinoza , p. 100. Spinoza refers the reader here to Descartes’ Principia

II 17–18, AT VIIIA 49–50; CSM I 230–31.

22 Bennett, Spinoza , p. 101. 23 Ibid.

24 Descartes’ view was that the present state of the world can be explained if we imagine an

initial state of disorder, which sorts itself out into swirls of fluid by way of the laws of motion

alone. These swirls of fluid, vortices, are what Descartes identifies with planetary systems,

a sun at the center of each, and planets circling about the sun. Essential to this account

is the assumption that all motion produces circular motion, which Descartes derives fromthe doctrine of the plenum. It is because all space is full, he argues, that all motion must

ultimately be circular, one hunk of material substance moving to make room for a given

moving body, a third hunk moving to make room for the second, and so on until a final

hunk moves to take the place left by the original moving body. In this way, Descartes’

whole cosmology depends on the denial of the vacuum. For the account of motion as

circular, see Principia II 33 (AT VIIIA 58–59; CSM I 237–39) and for the derivation of the

cosmos from an initial state, see Principia III 46ff. (AT VIIIA 100ff.; CSM I 256ff.).


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sions. There are a few interesting and, to the modern mind, very strange instances in which seventeenth-century philosophers usedempirical claims to support conclusions that we would consider philo-

sophical. The case is strange, and I’m not entirely sure I have it right,but Leibniz seems to have taken such a position. Leibniz held (or, at least, he often held) that animals are genuine substances, corporeal sub-stances. As substances, Leibniz argued, they cannot arise throughnatural means, nor can they perish by natural means. This is a conclu-sion Leibniz often establishes by pure philosophical argument; it is aconclusion of the celebrated predicate-in-notion argument of Discourse

on Metaphysics , §8,

25

and, Leibniz sometimes argues, of the no-less-philosophical principle of continuity.26 Leibniz also called on theexciting discoveries of microscopists like Leeuwenhoek and Malpighifor support. For example, he wrote to Queen Sophie Charlotte in May 1704 concerning an important consequence of his view of corporealsubstance:

Speaking with metaphysical rigor, there is neither generation nor death, but

only the development and enfolding of the same animal. . . . Experience con-firms these transformations in some animals, where nature herself has given

us a small glimpse of what it hides elsewhere. Observations made by the most

industrious observers also lead us to judge that the generation of animals is

nothing but growth joined with transformation.27

Microscopic examiners are being called upon to support one of thebasic propositions of Leibniz’s metaphysics, the natural ungenerability and incorruptibility of substance.

If this strikes us as being a bit strange, stranger still is Henry More, who calls upon the world of ghosts and goblins as empirical support forhis belief in the existence of incorporeal souls. In his Immortality of the Soul (1662 edition) More calls our attention to

such extraordinary Effects as we cannot well imagine any natural, but must

needs conceive some free or spontaneous Agent to be the Cause thereof,

whereas yet it is clear that they are from neither Man nor Beast. Such are


25 See C. I. Gerhardt, ed., Leibniz: Philosophische Schriften (Berlin: Weidmannsche Buchhand-lung, 1875–1890), 4:432–33, translated in Leroy Loemker, ed. and trans., Leibniz: Philo- sophical Papers and Letters (Dordrecht: D. Reidel, 1969), pp. 307–8. See also the letter to Arnauld, 28 November/8 December 1686, Gerhardt 2:76.

26 See Leibniz’s letter to Queen Sophie Charlotte, 8 May 1704, Gerhardt 3:345.27 Ibid. See the discussion of this and the references cited in Michel Serres, Le systeme de

Leibniz (Paris: Presses Universitaires de France, 1968), 1:354ff.


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speakings, knockings, opening of doors when they were fast shut, . . . shapes

of Men and several sorts of Brutes, that after speech and converse have

suddenly disappeared.28

That there are such happenings is, for More if not for us, an empirical

fact. For More these apparitions speak strongly in favor of souls distinct

from body: “Those and like extraordinary Effects . . . seem to me to be

an undeniable Argument that there be such things as Spirits or Incor-

poreal Substances in the world.”29 More may have been deluded in think-

ing that there are ghosts and obscure about how the phenomenon in

question is supposed to support his conclusion, but he certainly seemed

to think that the question of the existence of incorporeal substance, ametaphysical question par excellence, could be settled by a trip to a

haunted house. In this he was not alone. Hobbes, no advocate of imma-

terial substance, made a special point of denying the reality of ghosts

as part of his case against incorporeal souls.30 Although he did not

support the view More was pressing, Hobbes certainly seemed to think

that empirical evidence was germane to the question.

Why are these historical observations interesting? For one, they do

pertain to the proper interpretation of Spinoza and his contemporaries;

they suggest that we should be careful about attributing our distinction

between philosophy and science to earlier thinkers. There is a philo-

sophical lesson to be learned as well. My point is not that we should look

for philosophical truth in the sorts of arguments I was discussing; the

laws of motion shouldn’t be derived from God, nor should the ques-

tion of the vacuum be settled by an appeal to our intuitions about space

and extension. Nor do I think that metaphysical issues about the natureof substance can be settled by looking into microscopes, nor should we

consider seriously the ontological status of ghosts and goblins. Much

that was live in seventeenth-century thought is now dead, and I don’t

intend to revive it. The examples I have given do raise an interesting

question: Why is it that we tend to see such a radical break between phi-

losophy and science, and, more important, should we? The question can

be raised directly, without the need for history, as Quine has done. But

history brings the point home in an especially clear way: It shows us an

assumption we take for granted by pointing out that it is not an assump-

tion everyone makes.


28 Henry More, The Immortality of the Soul , p. 50, in A Collection of Several Philosophical Writings

of Dr Henry More (London: William Morden, 1662).

29 Ibid. 30 Hobbes, Leviathan , chapter 46; cf. chapter 2.


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Conclusion

Some years ago, an anthropologist friend told me something of what it

is like to do field work. When one enters a new community, she said, it is all very alien, an alien language, alien customs, alien traditions. After

a while things change; the language and customs become familiar, and

one is inclined to think that the differences are only superficial, that

the once-alien community is just like home. The final stage comes when

the similarities and differences come into focus, when one recognizes

what one’s subjects share with us, while at the same time appreciating

the genuine differences there are between them and us. The case issimilar for the history of philosophy. We cannot ignore the ways in

which past thinkers are involved in projects similar to ours, and the ways

in which we can learn from what they have written, how it can con-

tribute to our search for philosophical enlightenment. At the same

time, we cannot ignore the ways in which they differ from us, the way

in which their programs differ from ours, the way in which they ask dif-

ferent questions and make different assumptions. Both are important

to a genuine historical understanding of the philosophical past, but just as important, we as philosophers can learn from both.



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PART II

METHOD, ORDER, AND CERTAINTY


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2

DESCARTES AND METHOD IN 1637

The Discourse on the Method and the three essays that were published with

it, the Dioptrics , the Meteors , and the Geometry , make up a very curious

book. The very title page emphasizes the preliminary discourse, and

that discourse, the Discourse on the Method , emphasizes method, the

importance that method had for Descartes in making the discoverieshe made, the importance that the method Descartes claims to have

found will have for the progress of the sciences and for the benefit of

humankind as a whole. Descartes is not, of course, telling us that we

are obligated to follow his method; the Discourse is, after all, proposed

“as a story, or, if you prefer, as a fable” (AT VI 4). But Descartes expects

that we will all see the light, the light of reason, of course, and follow

his example. It is curious, then, that Descartes gives the reader only brief hints of what that method is, four brief, vague, and unimpressive

rules that, taken by themselves, would hardly seem to justify Descartes’

enthusiasm, not to mention a whole discourse in their honor. Further-

more, explicit methodological concerns are hardly in evidence in the

Dioptrics , the Meteors , and the Geometry , which are, Descartes claims,

“essays in this method,” as he identifies them on his title page. Indeed,

one is hard pressed to find much evidence of the method at all after

1637, either explicit discussions of the method or explicit applicationsof the method in any of Descartes’ writings, published or unpublished.

Very curious.

These observations raise quite a number of questions about the

development of Descartes’ thought and the state of his program as of

1637. In this essay I shall address two of these questions: (1) What pre-

cisely was the method Descartes had in mind in 1637, when he sang its

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praises so enthusiastically? and (2) Why does that method appear so

little in the publications of 1637 and appear to drop out altogether

after that? Briefly, I shall argue that the method of 1637 was just the

method Descartes had put forward more clearly in the earlier Rules for the Direction of the Mind , or, at least, the dominant method that shows

through the latest stages in its composition. But, I shall argue, perhaps

by 1637 and certainly after, that method began to show its limitations,

and the method that was one of Descartes’ first discoveries, one of

his first inspirations proved itself inadequate to the mature program

that it led Descartes to undertake. Obviously there is not the space to

present the detailed discussions these questions require. But I shalltry to present in broad strokes one way of understanding the develop-

ment of Descartes’ methodological thought as he passed from youth to

maturity.

I

I have claimed that the method of 1637 is essentially the method of the

Rules for the Direction of the Mind , and to make good on that claim, wemust first turn to that work. The Rules , started as early as 1619 and aban-

doned in 1628, is a very difficult work; despite its superficial organiza-

tion, it is often strikingly unmethodical and disorderly for a work that

is supposed to be Descartes’ most systematic exposition of his method.

It is blatantly a work in progress that never progressed to anything like

a finished draft, and the text we have shows obvious signs of having

been picked up and put down at different times throughout the periodof composition.1

To begin unraveling Descartes’ complex thought on method in the

Rules we must look to the earliest strata of the work, where Descartes

sets out the goal of the method in passages likely to have been written

in November 1619, shortly after the dreams of November 10.2 Descartes

wrote:

34 method, order, and certainty

1 For questions of dating, see J.-P. Weber, La constitution du texte des Regulae (Paris: Société

d’édition d’enseignement supérieur, 1964). Weber believes that Descartes wrote the text

of the Rules in ten discrete “phases.” Though the stages of composition are difficult to dis-

tinguish with such exactitude, Weber’s arguments are often useful for dating particular pas-

sages of the Rules . I have also used datings suggested by John Schuster in his “Descartes’

Mathesis Universalis , 1619–28,” in S. Gaukroger (ed.), Descartes: Philosophy, Mathematics and

Physics (Sussex: the Harvester Press, 1980).

2 See Weber, La constitution , §§ 13, 55.


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The goal [ finis ] of studies ought to be the direction of one’s mind [ingenium ]

toward having solid and true judgments about everything which comes

before it. (AT X 359)

But, Descartes thinks, such “solid and true judgments,” such “certain

and indubitable cognition” (AT X 362) as he calls it in the following

rule, can come to us in only two ways, through intuition, or through

deduction, “for in no other way is knowledge [scienti

descartes embodied

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