Gilbert of Poitiers

Luisa Valente

Abstract

Born: Poitiers after 1085, Died: Poitiers 1154. According to Gilson,Gilbert was the greatest metaphysician of the twelfthcentury. He was a profound thinker, original and coherent,famous in his time for the complexity and boldness of hisphilosophical theology. He provoked both violent disapprovaland great enthusiasm. Brought to trial for heresy in 1148,he came out of it without being condemned; rather, histhought had a considerable number of followers in the so-called ‘Porretan School’. Through his followers he exerciseda significant influence on the theology of the second halfof the 12th century. In his mature thinking, he went farbeyond what he had learned during his apprenticeship: atChartres, philosophy of a Platonic stamp based on theTimaeus and on the Consolation of Philosophy and Opuscula sacra ofBoethius; at Laon, theology founded on Biblical exegesis andthe Fathers. In his Commentary on Boethius’s Opuscula sacra,his fundamental work, he developed a profoundly innovative‘rational’ theology and an autonomous and broadly coherentphilosophical reflection. It combines the Platonic doctrineof the preeminence of form with a keen sense of the primacyof the concrete and the singular. It consists of,principally, an ontology, a philosophy of language and anepistemology, all closely inter-connected. Only theprinciples (God, prime matter, ideas) are simple, and onlyin God is being everything that he is. Created entities, bycontrast, receive their being from something other thanthemselves (from God) and they are composed of an orderedaggregation of forms. Forms are always inherent in asubstrate. Common natures do not exist; everything,compounds and forms, is singular: the humanity of every manis similar to but different from that of any other man. Butnot everything that is singular is an individual – onlyconcrete entities and the compounds of forms that constitute

the complete form of every concrete entity are individuals:their individuality consists in the fact that, if they areconsidered as wholes, they are dissimilar from any othercompound thing. Universals are collections of singular formsgathered together by the intellect on the basis of theresemblance which is found between the singular entities. Aname signifies a concrete entity and one of its propertiesor forms; the subject of the proposition represents theconcrete entity, and the predicate represents a forminherent in it. The language of the philosophy of naturereflects what it investigates: the compound constitution ofcreation. It lends its own terms and its own formalstructures to the other two speculative sciences,mathematics and theology. The correct understanding of atext is attained when, by distinguishing the appropriatediscipline to which it belongs, the interpreter gathers,beneath the surface of the words the ‘meaning in theauthor’s mind’.

1. Biography, apprenticeship, and generalcharacteristics of his philosophy

Gilbert was born in Poitiers shortly after 1085 andbegan his studies there under Hilary of Poitiers. Later hemoved to Chartres where he was one of the students ofBernard. At Poitiers and Chartres he studied the liberalarts, in particular grammar, dialectic and rhetoric – inwhich his knowledge was legendary – and Platonicphilosophy. He studied Plato’s Timaeus with Calcidius’scommentary, and Boethius’s Opuscula sacra and Consolation ofPhilosophy. From Chartres he moved to Laon, where underAnselm and Ralph he was educated in the understanding of theFathers and Scripture. He was a master at Chartres from1124 at the latest (at least according to most scholars, butsee Gross-Diaz, 1996), and, starting some time between 1137and 1141, at cathedral school of Paris, where he had John ofSalisbury among his students. John remarked that histeaching appeared obscure and arcane to the beginners, butthat the experts, used to his original terminology and

complex style, found it to be of great profundity. Histeaching at Paris was cut short in 1142 when he was namedBishop of Poitiers, where he died in 1154. The rational andphilosophical style of doing theology earned Gilbert, amongothers, an accusation of heresy by Bernard of Clairvaux (whoalso persecuted Abelard), from which he had to defendhimself in front of the Pope in 1147, and later, in 1148(Maioli, 1979: XVI-XXI; Nielsen, 1982: 30-38). He wasaccused, in particular, of holding that the divine naturewas identical, not with God but with a form, just as in thecase of humanity, which is not identical to man but with theform thanks to which a man is a man; and of holding that theproperties (generatio, filiatio, processio) through which the threepersons of the Trinity are distinguished are distinct fromthe persons themselves (Pater, Filius, Spiritus Sanctus). AlthoughGilbert emerged from the trial without being formallycondemned, there remained an aura of suspicion about him andhis work. None the less, his thought and his specialterminology were appropriated, and reworked to variousdegrees, by a certain number of thinkers working in thesecond half of the twelfth century, who are usually knowncollectively as the ‘Porretan School’ (Marenbon, 1988;Marenbon, 2002; Catalani, 2009). These masters in turn, andin particular Alain of Lille, exerted an influence on otherteachers of the period, above all with regard to thesemantics and the logic of theological language (Valente,2008a). Among the works of Gilbert, the fundamental one ishis Commentary on the Opuscula sacra of Boethius (except forDe fide catholica), edited by N.M. Häring. Other certainlyauthentic works, unedited except for some fragments, are acommentary on the Psalms (studied by Gross-Diaz, 1996) andone on the epistles of St. Paul (some passages are editedand discussed in Nielsen, 1982). Various other writings thathave been attributed to Gilbert by editors have been foundto be inauthentic (Nielsen, 1982: 40-46); in particular, theso-called Liber sex principiorum, already attributed to him byAlbert the Great (Lewry, 1987), is not Gilbert’s.

2. Ontology

2.1. Forms and SubstancesThe ontology of Gilbert (general accounts in Jolivet,

1992b: 141-146; Marenbon, 1998: 168-171; Jacobi, 1996: 12-14; Jacobi, 2002: 74-76), which has pertinently been calleda ‘metaphysics of the concrete’ (Maioli, 1979), is acombination of doctrines, broadly coherent, but not withoutindeterminate elements. It is distinguished from thephilosophy of nature practised at Chartres by, above all,the theory of forms, of individuals and of universals. Italso adopts an original vocabulary, whose basic elements arethe terms: subsistens, subsistentia, concretio, tota forma.

Subsistens (which will be translated below as‘subsistent’) corresponds to Boethius’s id quod est (Dehebdomadibus), i.e., ‘the <thing> which is’ (cfr. de Rijk,1988: 75), the determinate entity, which is such from theinherence of a multiplicity of forms. As a synonym forsubsistens Gilbert uses the term substantia, in virtue of thefact that it ‘is under’ (sub-stat) the accidents; substantia,however, is ambiguous, because it is also able to refer toforms.

Subsistentia (‘subsistence’) corresponds to the esse or idquo est of Boethius, ‘that through which the <thing> which isis’, the formal principle which makes the subsistent existand which confers on it its substantial properties. Thesubsistentia is referred to also as natura, nativorum forma, esse.The subsistentiae can be simple or composed of othersubsistentiae: humanitas is composed of animalitas and rationalitasetc. Of the subsistent Gilbert says that ‘it has’ (habet)the subsistentiae, or ‘participates’ (participat) in them. Toinclude under one general name both subsistents andsubsistences, Gilbert uses the neutral plural (e.g.,singularia) or the term substantiae. In the constitution of thesubsistent, the accidental forms are added to thesubsistence: they confer on the subsistent its accidentalcharacteristics of quality and extension (quantity).

Concretio (‘concretion’) is a term which refers to theordered aggregation of the many subsistences and accidentalforms which constitute the subsistent. These forms support(con-crescere) one another, beginning from the more generic

and descending gradually in ever increasing determinateness:they are related to one another as generales and differentiales;in this way the formal structure of the subsistent followsthe order of Porphyry’s tree. The more general forms arethe causes of the increasingly less general forms thatadhere (adsunt, adhaerent; e.g., albedo to corporeitas) to them,in a relation of consequence (complexionis consequentia). Thefirst subsistence, the most general, is preceded only by theprimary cause and constitutes the basis of the process ofordered aggregation of forms that constitutes the subsistent(Comm. De hebdomadibus, p. 209, ll. 67-85). It is not clear,however, if this first subsistence is a maximallyindeterminate substantial form which ‘precedes’ thecorporeitas and the spiritualitas, the two most general formswhich distinguish the corporeal from incorporeal things, orif it is one of these two.

Tota forma (‘complete form’): the subsistences of a singlesubsistent taken together and in their totality constitutethe tota or propria forma or proprietas (in the case of Socrates,it can be called socrateitas), which confers to the subsistentat a time that it is something and its unity. The tota formais made up of all the subsistences and all of the accidentalforms of quality and extensive quantity which the subsistentactually (actu) has had, has, and will have in the future,and even those which it will never have, but could possiblyhave according to the potentiality of its own nature (naturâor potestate: Comm. De trinitate p. 144, ll. 75-77; cf Comm. ContraEuticen p. 274, ll. 81-82). In one passage Gilbert says thatthe forms that constitute a complete form are infinite(Comm. De trinitate p. 90, l. 50). The numerousness of the formswhich make up the complete form, which extends to the futureand the possible, makes impossible an adequate understandingof this by man: finite reason cannot but proceed throughpartial representations of things (Maioli, 1979: 46; Jacobi,1995a: 80 s.; Jacobi, 1996: 14). The unifying principle thatholds together in an individual and organic whole thetotality of the substantial and accidental forms thatconstitute the tota forma is God as simplex auctor or qui est solum

bonum (Comm. De hebdomadibus, p. 219, ll. 42-57), from whichevery subsistent ‘flows’ (fluxit: p. 220, l. 81). Yet Gilbertalso speaks of the unitas of the subsistent as deriving fromthe ‘accidental unity’ (unitas coaccidens) that accompaniesevery form, substantial or accidental (Comm. Utrum Pater, p.176, ll. 15-22). The accidental determinations of non-extensive quantity and the other seven categories do notmake up a part of the total form; these seven categories donot correspond to forms but only indicate extrinsicrelations that the subsistent maintains with othersubsistents (extrinsecus affixa, status).

As can be seen, concepts of simplicity and compositionare fundamental to Gilbert’s ontology. Entities are eithersimple or composite. Above all, the principles, also calledgenuina, that constitute the object of theology – God,prime matter (yle, silva), the archetypal ideas – are simpleentitities because they do not derive their being from amultiplicity of other entities. In the Commentary onBoethius, Gilbert does not dwell on the contrast between thetheory of the plurality of principles and Christiandoctrine, while in the biblical commentaries he adoptsAugustine’s view of the creation of matter (Jolivet, 1992a).The forms or subsistentiae which go on to constitutesubsistents originate as images or copies or reflections(the manner of this derivation is not better specified) ofthe exemplary (exemplar, ydea) ideas. Of these forms, thoseare simple which are not in turn composed of other forms,like corporeitas or albedo; but they are not simple in the samerespect as the principles, as the forms do not exist if theyare not within a compound. In fact, almost everything whichis not a principle is composite – that is to say, createdsubsistents (nativa) and the greater part of their forms.Subsistents are composite both in the sense that, in orderto constitute them, their esse or formal principle mustinhere in something (this type of composition is calledconiunctio), and in the sense that their complete form isconstituted of a multiplicity of forms (concretio). Moreoversome subsistents are made up by putting together a number ofsubsistents as their parts, such as man, constituted of his

body and his soul, which constitute his parts, each withtheir own forms. The forms of the subsistent parts are atthe same time forms of the whole subsistent: the rationalityof the soul of Socrates and the whiteness of his body arethe rationality and whiteness of Socrates.

The moment of origin of the constitution of a subsistentthrough the coniunctio of esse in it is the divine act whichmakes the forms inhere in the subsistent. It is calledgeneratio or creatio. With respect to this original moment, thetheory of Gilbert seems to present a serious problem: “whatthe quo est makes into the quod est cannot be the quod est itself– so what is it?” (Marenbon, 1998: 169). A possible responseis that there is no substrate, in which the forms inhere toconstitute the subsistents, except for a subset of the formsthat constitute the whole; so that, supposing we werementally to abstract all the forms from the subsistent,nothing would remain: ulitmately, the subsistent would beidentical with the total form. But this solution is aspeculation which goes beyond Gilbert’s text (Jacobi, 1996:16). Another possible reply, closer to Gilbert’s text, isthat the original substrate in which the forms inhere is the‘primordial cause’ which is spoken of in Comm. Dehebdomadibus (p. 209, ll. 67-85), that ‘precedes’, in theconcretio, the most general form. But the problem remains,what is this primary cause: prime matter, God, the ideas? Inany case, how is the most general subsistence related to theprimordial cause? The response that Gilbert would probablyhave made is that man cannot give an answer to thisquestion, as his knowledge, discursive and distinct, islimited to the world of compounds (philosophy of nature) andthe forms abstracted from these (mathematics), and cannotraise itself so as to grasp their relation with the absolutesimplicity of the principle from which they originate.

2.2 Singularity and modal theory of individualityGilbert’s theory of individuality is clearly distinct

from a long tradition, in which Boethius, Eriugena, Anselmof Canterbury, William of Champeaux, Thierry of Chartes, butnot Abelard concur (called STI: “Standard Individuation

Theory” by Gracia, 1988; cfr. Maioli, 1974: LI-LII).According to STI it is the accidents alone which makeindividuals of the same species being numerically one andthe same unique ‘communal quality’ (qualitas communicata) isfound complete (tota) in every individual of the samespecies: Cato and Cicero are one identical entity – idem –in that, belonging to the same species Man, they share thesame humanitas; whilst they are numerically different fromone another – plures – only because of the diversity of theiraccidents. For Gilbert, rather, the numerical diversity ofsubsistents is due, not only to the accidents, but to all ofthe forms, accidental and substantial, which come togetherto constitute them: there exist as many diverse humanitatesas men. The differences in the accidents do not provide thebasis for the numerical diversity of subsistents, but merelyindicate it. Singularity, i.e., being numerically one, is anintrinsic characteristic of every entity, whether it is acompound or a form, and is presented in Gilbert’s ontologyas a primary, non-deducible given. Moreover, unlike hispredecessors, Gilbert in consequence considers the conceptsof singularity and individuality to be different. The set ofindividuals is a subset of the set of singulars: everythingthat exists is singular, but not all that exists is bothsingular and individual. Only subsistents and complete formsof subsistents are singular and individual. The subsistent(e.g., Socrates) and the tota forma of each subsistent(socrateitas), are singulars and individuals, that is to saynot dividuals, because they are not similar to any otherentity either in act or just in potency (Comm. Contra Euticen,p. 272, l. 45-274, l. 93). By contrast, a form is dividualwhich, whether simple (rationality) or compound (humanity),turns out to be, judging from its effects, similar to otherforms, if not in act then at least in potency. On the basisof this similarity these forms are said to be conformes toeach other (the humanity of Socrates and that of Plato aresimilar in potential and in act; the being-the-sun of thesun is similar not in act but at least in potential to thebeing-the-sun of another sun which does not exist, did notexist, and will never exist, but could exist: Comm. Contra

Euticen, p. 273, ll. 68-74). Finally, those entities which,though dissimilar from every other entity, are none the lesspart of another individual are not themselves individuals,for they share their own formal characteristics with thecompound whole. The soul is not therefore an individualsince it shares its formal characteristics with man, ofwhich, with the body, it is a part. Since it is not anindividual, the soul is not a person either, according tothe Boethian definition of the person as “naturaerationabilis individua substantia” (Comm. Contra Euticen, p.271, l. 14 – 274, l. 95). It should be observed, however,that Gilbert gives this definition with an importantclarification and modification: the clarification is that noperson can be part of a person; the modification is that forhim the characterization of person as rational is purelyconventional, due to the usage of philosophers. Strictlyspeaking, even plants and animals are persons: for they areindividual substances which are each dissimilar to everyother entity and are not parts of any further compoundentity (Comm. De trinitate, p. 146, ll. 14-23). In this sense,it would seem that Gilbert does not make a real distinctionbetween person and individual (Elswijk, 1966: 192; Maioli,1979: 339; but the interpreters disagree over Gilbert’scharacterization of the concept of person; cf. Nielsen,1982: 62-64; Marenbon, 1988: 346; Jacobi, 1996: 17-19).

It has been observed (Knuuttila, 1987 and Knuuttila1993: 75-82, recalling Nielsen, 1982: 62-64, 180, 184) that,since he considers that the properties the subsistent doesnot ever effectively possess but could possess according tothe potency of its own nature are parts of the total form,he is proposing a ‘modal’ theory of individuality. Thisconception presupposes the idea of possible worlds andpossible alternative histories of the world and theconviction, not really argued for, of the stability ofindividual identity across various possible worlds andvarious possible histories (Knuuttila, 1993: 81). ButGilbert’s modal definition of individuality seems to havethe undesirable consequence of dissolving the veryindividuality he wishes to define: indeed, if taken

literally, Gilbert’s definition seems to imply that thecomplete form of every individual of a species includes allthe possible determinations of every other individual ofthat species. It follows that the complete forms ofindividuals of the same species would all be similar to eachother, and so dividuae (Marenbon, 1998: 171). Gilbert’sappeal to a modal definition of individuality, and thus tothe idea of different worlds and histories, can be traced toa keenly felt need to conserve as far as possible God’somnipotence which is not subject to any necessity whatsoeverexcept in that of certain basic rules of logic set out inthe theory of topical argumentation. Of which parts thevarious subsistents are composed, and of which general,differential and accidental subsistences the complete formsof the subsistents of different species are composed alsodepends on God’s omnipotence and will and is not necessaryin an absolute sense. Such compositions are governed by themerely relative necessity of the habitual course of things(consuetudo rerum) and of the usual condition of naturalbeings (usus nascentium, qui vocatur natura: Comm. De trinitate, p.164, ll. 34-41; Comm. Contra Euticen, p. 304, ll. 83-91).

2.3. Universals and the Realism of FormsAccording to Gracia (1988: 164) the bases of Gilbert’s

doctrine of universals are constituted by two postulates:the singularity of everything, whether forms or subsistents;and the individuality of the complete forms of subsistents,and of subsistents themselves which are not parts of anycomposite. In addition to these, there is the similarity(similitudo) or conformity (conformitas) between singularentitites, both subsistences and subsistents. Indeed, eventhough the latter are individuals and thus different fromevery other being, they are, nevertheless, similar todifferent groups of other individuals if their formaldeterminations are considered separately (Socrates issimilar to Plato and to Cicero if one considers theirrespective whiteness, rationality, etc.). According to VanElswijk (1966: 200), the similarity between groups of beingsseems to be a third postulate of Gilbert’s ontology. But

Maioli (1974: 326-328; 1979: 344-347) maintains that, forGilbert, the conformitas is to be explained by the derivationof native forms from exemplary ideas. Whatever the case, theuniversal (genus or species) is a collection (collectio) of amultiplicity of forms which are, in themselves, singular. Itis constituted by the intellect on the basis of similaritiesapprehended between groups of singular entities that areconform. According to Gilbert – who in this respect can beplaced beside Abelard – the unity of a species, like that ofa genus, does not correspond to any common nature but is theproduct of abstraction (“humana ratio abstrahit”) andlanguage (“dicuntur unum et idem”). At the level of realityonly singular beings exist, some of which are alsoindividuals, which are grouped into those similar to eachother (Maioli, 1979: 341-364; Valente, 2008b). Inasmuch assubsistences are formal constituents of particularsubsistents one can speak of a “realism of forms” in Gilbert(Jolivet, 1992b). However, one certainly cannot speak of arealism of universals, even though his theory seems topostulate a foundation in re of the universal, consisting inthe similitudo or conformitas of individuals belonging to agroup according to the consuetudo rerum.

3. Philosophy of Language3.1. HermeneuticsGilbert’s philosophy of language takes as its starting

point the Boethian-Aristotelian triad vox-intellectus-res (Deinterpretatione 16a4) and the grammatical conception of namesas signifying substances and qualities (Priscian, Institutionesgrammaticae II, 18 and 19). But what distinguishes it aboveall is its ‘pragmatic’ and ‘hermeneutic’ approach: languageis perceived principally as an instrument for communicatingmeaningful contents between human beings. Gilbert very oftenrefers to the speaker (locutor), the author of a written text(auctor), the hearer (auditor), the reader (lector), theinterpreter (interpres); he speaks of the sense or concept inthe mind of the one who speaks (sensus/conceptus/intellectus mentiseius, qui loquitur) and of the vigilance (vigilantia), attention(attentio) and intelligence (intelligentia) of the addressee. In

Comm. De Trinitate, prol., 21-24 he brings to light anintrinsic and inevitable discrepancy between the threelevels of language, thought and reality, both from thespeaker’s point of view (from the res through the concept tothe word) and from that of the interpreter (from the wordthrough the concept to the res). Although things can bethought thanks to concepts and signified through words, therange of the real is much vaster than that which can beconceived in thought. The sphere of thought is, in turn,much broader than the sphere of what can be expressed inwords. This is true both for discourse about God and forthat about creatures. There cannot be a concept of God nor aproper way for him to be expressed, because of hissimplicity, which does not allow any particular aspect to beisolated in a concept or word. Analogically but inversely,an adequate concept of a creature cannot be formed due tothe inexhaustible complexity of its formal structure.Language is even weaker than thought because of the frequentlack of appropriate words (inopia verborum), the improper useof language (translatio, usus), and the inevitable ambiguity ofmany terms (multiplicitas, ambiguitas). As a consequence (Jolivet,1998; Valente, 2004: 168-171), the correct interpretation ofa text requires taking this discrepancy into account: itwould be misleading to believe that one could pass directlyfrom the intellection of spoken or written words (intellectusquem scripta faciunt) to the truth of things. One should beconstantly aware that these two instances are mediated bythe thought of the author of the text (intellectus ex quo <scripta>facta sunt) – a thought that corresponds only to a certaindegree to the letter of the text as it has been written, onthe one hand, and to the reality of things, on the other.Starting from taking into consideration in this way themediating role of the concept in the mind of the author, theprocess of interpretation unfolds. From the letter of thetext (significatio) the interpreter seeks, above all, to reachthe thought of the author (conceptus – or intellectus – auctoris)in order to judge the written text in relation to it.Second, the interpreter seeks to specify in what measure theauthor’s thought grasps the truth of things, in the constant

awareness that this measure is necessarily limited, and toevaluate the discourse that has been made in relation to thethings themselves that have been conceived. It isparticularly important to take into account the conceptusauctoris when analysing theological discourse, which is alwaysimproper in its literal meaning and is to be interpretedtaking into account that it is inevitably based on an(albeit non-arbitrary) transposition of terms and linguisticforms taken from natural philosophy (proportionalis transumptio).Besides the conceptus auctoris, another aspect to be takenaccount of in the interpretation of a text, in everydiscipline, is usage (usus, auctorum usus), which does notalways respect lexical proprieties or syntactic rules andwhich, in time, can also modify the meaning of terms fromthat of their original institution (vis/natura nominis).Moreover, according to Gilbert, a fundamental requirementfor reaching a true understanding of a text and avoidingmisunderstandings is to pay great attention to thepropositional context (ratio propositi). Gilbert refersparticularly to the vigilantia lectoris and the ratio propositi,becaue it is well known that propositions with the same nameas subject, but are placed on different disciplinary levels– such as those of the philosophy of nature, of logic andof mathematics (see below) - speak of different things. Thedetermination of the level of discourse to which a passagein fact belongs is not attributed, as in the logic of terms,to the distinction between different forms of suppositio (aconcept Gilbert himself often uses, almost always in thesense of a reference to subsistents by way of the subjectterm of a proposition: Valente, to be published) or, as isthe case in certain logical and theological texts of thetwelfth century, to the identification of a particularimproper rhetorical use of language (transumptio, translatio;cfr. Keepkens, 2000: 257). Rather, Gilbert proposes areconstruction and general contextualization of whatever isbeing considered in order to arrive at a correct intelligentiaof a text in each of the different sciences: besides thegrammatical and logical rules and the improper use oflanguage studied in rhetoric, one should consider the nature

of things, as taught by the philosophers, as well as theintention of the author. Whoever remains attached to wordsand their functions, and does not seek to understand beyondand above them the “meaning in the mind of the one whospeaks”, understands neither others nor himself and is asource of great danger (Comm. Contra Eutichen, p. 296, l. 31 –298, l. 97).

3.2. The Meaning of Nouns and the Theory of Predicationin the Philosophy of Nature

Gilbert’s theories of the meaning of names and ofpredication are intrinsically connected not only to thegrammatical conceptions of his time which derived from aPlatonic reading of Priscian’s grammar, and to thefoundations of the logica vetus, but also to his own personalontology. Ordinary language, to which the language ofnatural philosophy is led back, reflects the ontologicalstructure of created reality, albeit in the limited manneralready discussed (Jacobi 1995a: 96-100). If Priscianaffirms that the noun signifies substance and quality, thisis to be understood in the sense that it signifies both thesubsistent and the subsistence or form. Homo signifies asmuch the particular man (substantia nominis, id quod est) as theform humanitas (qualitas nominis, id quo est). It is for thecontext (ratio propositi) to suggest which of the two meaningsis actually intended by the author in differentpropositions: in “Homo est risibilis” the singular man, in“Homo est individuorum forma” the form humanitas (Comm. ContraEutichen, p. 296, l. 31 - 297, l. 66). Like the significateof the noun, predication also reflects the duality ofsubsistents and forms that dominates the created world(Maioli, 1979: 79-99). In natural non-metaphorical discoursethe author refers to (supponit) by means of a noun in thesubject-position the subsistent or id quod est as that ofwhich is being spoken; through the predicate the authorexpresses the inherence of the form or the id quo est whichthe predicate signifies in the subsistent referred to by thesubject term: in “Socrates est homo”, “est homo” expressesthe inherence of the form humanitas in the individual

represented by the name ‘Socrates’. Every subsistent hasmany names according to which of the forms it is beingconsidered under: Socrates is called ‘Socrates’ if hisproper form socrateitas is being considered, ‘white’ if hisaccidental form of whiteness is being considered, ‘man’ ifhis substantial form of humanity is being considered, and soon. When a proposition is formulated to affirm somethingabout the subsistent, first of all one of its possible namesis chosen in order to indicate it as the object ofdiscourse. But such names are chosen in view of what onewishes to predicate: “we do not predicate in order tosupposit so much as supposit in order to predicate” (Comm.Contra Euticen p. 349, l. 50 s.). Among the predications ofnatural philosophy which are true in a proper sense, in somethe form signified by the predicate stands in a relation ofconsequence to that signified by the subject, which is itscause according to the internal order of the agglomerationof generic and specific forms that constitutes thesubsistent (complexionis consequentia). For example: “corporeumest album” – given that the form of whiteness is an effectof corporeity; corporeity cannot exist without some colour-form. Such propositions are called consequentes. But thereare also cases of propositions which, although they have theexternal form of subject + predicate and are true in aproper sense and not the result of metaphorical discourse,nevertheless do not respect the complexionis consequentia. Anexample is “corporeum est rationale”: although Socratesreally is corporeal and rational, there is no relation ofconsequence between his form rationality and his formcorporeity. For rationality is caused by the spirituality ofSocrates’ soul and not by the corporeity of his body,signified by the term corporeum. Such propositions arecalled accidentales tamen verae conexiones and provide a model forinterpreting various theological propositions. For example,the proposition “God has died” is true since Christ is Godand Christ has died, even though he died inasmuch as he wasa man, and not inasmuch as he is God (Comm. Contra Euticen p.345, l. 29 – 348, l. 8; de Rijk 1987: 164-170). Thepredications of natural philosophy are also further

distinguished in relation to the substantial or accidentalfunction within the ontological structure of the subsistentof the form signified by the predicate, as well as inrelation to Aristotle’s classification of the ten categories(Maioli 1979, 83-101; Comm. De Hebdomadibus, p. 198, ll. 76-90). Substantial predications express the irreplaceableelements which cause a subsistent to be and to be thisparticular subsistent – its subsistentiae, the forms which makeup its substantial being (esse aliquid in eo quod est). Accidentalpredications express characteristics of a subsistent whichmay or may not be found in it without producing ordestroying its being or its being this or that particularsubsistent. They express only its accidental being (tantumesse aliquid). A further, different distinction is made betweenpredications secundum rem or inhaerentium and those that areextrinsecus comparatae or non inhaerentium (De trinitate, p. 134, l.77 – 138, l. 78). Independently of their being accidental orsubstantial to a given subsistent, the forms signified bypredications of substance, quality and extensive quantityare always inherent in the subsistent and the predicationswhich express them are thus “according to the thing”. On theother hand, predications of non-extensive quantity as wellas of the remaining seven categories express, despite theirsubject-predicate form, not true inherence but externalcircumstances or relations of various types betweensubsistents and things other than themselves (status).Gilbert therefore calls them “extrinsically compared”.

3.3. The Three Speculative SciencesGilbert mentions a broad range of branches of human

knowledge. In Comm. De trinitate (p. 115, ll. 3 s.) he lists thefollowing facultates: naturalis, mathematica, theologica, civilis, rationalis,which differ on the basis of the different genera of theirrespective objects of study. In Comm. De hebdomadibus, p.189, ll. 52-60 he considers the disciplinae: mathematics, ‘adiscipline of the highest rank’, which consists of the fourarts of the quadrivium: arithmetic, geometry, music andastronomy; as well as the “other disciplines such as thoseof the Categories and the Analytics”. In all these

disciplines, one proceeds by way of demonstration, beginningfrom terms or rules which constitute the starting-points fordeduction and induction. Central to Gilbert’s system,however, is the triad of speculative sciences which consistsof physics or philosophy of nature, mathematics andtheology, which is set out by Boethius in his Commentary toPorphyry’s Isagoge, second edition, and in the De trinitate, butgoes back to Aristotle (Haas, 1987; Jolivet, 1990; Jacobi,1995b). Natural philosophy studies concrete subsistents andtheir inherent forms. It is the fundamental science in thesense that from it take splace the transfer (transumptio) ofterms and forms to all the other sciences. In Gilbert’ssense of the term (which is not the usual one) mathematicsconsiders forms, which in reality can only exist insubsistents, as abstracted from them. Thus, in mathematicspredications (for example, “homo est individuorum forma”)express only an apparent inherence. The case of theologicalpredication is analogous, because in God there is nodifference between form and subsistent, so that in theologypredication does not express any inherence and is thereforenot predication in the strict sense. Due to the lack ofadequate expressions for speaking about God, the patristicauctoritates and the theologians transfer and apply improperlynames and categories proper to natural scientia and, thus, tonatural language. But they do so on the basis of naturalproportion (rationis proportio). And so when, for example, it isstated that God is a substance, or a certain substance, thisshould not be understood in the same sense as when it isstated that something is a substance in non-theologicaldiscourse. The ratio for which something can be said to be asubstantia is its substare; subsistences as well as subsistentsare called ‘substances’ inasmuch as they serve as substrates– substant – for accidents. But in God there is nodistinction between substance and accident. Therefore, whenthe category of substance is predicated of God, it is doneimproperly, on the basis of the ratio according to which God‘sustains’ all things (“substat omnibus”; Comm. Contra Euticen,p. 284, ll. 74-90) as cause and principle. At the same time,however, it is God alone who properly is in the fullest

sense, just as it is of God alone that one can say in a fullsense that he is good. All other things that are not God areand are good in a lesser and derived sense, that is, througha denominativa transumptio o transumptiva denominatio (Jolivet, 1987;Valente, 2008a: 123-149). As can be seen, in philosophy ofnature and in theology a chiastic relation between languageand being is established: on the level of language,discourse about nature founds the discourse about God,whereas on the ontological level it is the divine beingwhich is the foundation and source of created being (whichderives from it through fluxus). Moreover, given that namesin natural discourse denote objects on the basis of theirforms, discourse about nature could not be constituted ifthere were not, thanks to mathematics, a way of consideringseparately forms which in reality are inseparable fromsubsistents. Yet natural discourse not only lends the termsand formal structures for theology but also for mathematicsitself, in the discourse of which they are used differentlyfrom their original definition and from the valid norms ofnatural discourse. The three speculative discourses are thusinterrelated in a complex way, by reciprocal foundationalrelations and transfer of terms and formal structures. Therole of mathematics as a discipline, however, was not welldefined by Gilbert and would be given closer attention bysome of his followers (Marenbon, 2002).

See also12th Century Schools; Alain of Lille; Being; Boethius;Metaphysics; Modal Logic and Modal Theories; NaturalPhilosophy; Platonism, Medieval; Supposition Theory;Trinity; Universals.

Bibliography

Authentic works in complete editions:

- Commentaria in Boethii Opuscula Sacra, ed. N.M. Häring, TheCommentaries on Boethius by Gilbert of Poitiers, Toronto: PIMS, 1966(Studies and Texts 13). Some particularly important passageshave been translated into English in de Rijk, 1988-89.

Secondary sources:- Catalani, L. (2009), I Porretani. Una scuola di pensiero, tra alto ebasso medioevo, Turnhout: Brepols (Nutrix 2).- Colish, M. (1987), “Gilbert, the Early Porretans, andPeter Lombard : Sematics and Theology”, in Jean Jolivet etal. (eds.), Gilbert de Poitiers et ses contemporains, 229-250.- Gauvin, J. (1987), “Les sens de ‘nichil’ chez Gilbert dela Porrée”, in Jean Jolivet et al. (eds.), Gilbert de Poitiers etses contemporains, 173-181.- Gracia, J.E. (1988), Introduction to the problem of individuation inthe early Middle Ages (2nd ed.), München and Wien: PhilosophiaVerlag, in part. 155-178.- Gross-Diaz, Th. (1996), The Psalms Commentary of Gilbert of Poitiers:From Lectio Divina to the Lecture Room, Leiden-New York-Köln:Brill (Brill's Studies in Intellectual History 68).

- Haas M., “Die Wissenchaftsklassifikation des Gilbert vonPoitiers”, in Jean Jolivet et al. (eds.), Gilbert de Poitiers et sescontemporains, 279-295.- Häring, N.M. (1957), “Sprachlogik und philosophischeVoraussetzungen zum Verständnis der Christologie Gilbertsvon Poitiers”, Scholastik 32, 373-398.- Kneepkens, C.H. (2000), “Grammar and Semantics in theTwelfth Century : Petrus Helias and Gilbert de la Porrée onthe Substantive Verb”, in Maria Kardaun and Yoke Spruyt(eds.), The winged chariot: collected essays on Plato and platonism inhonour of L.M. de Rijk, Leiden – Bostin - Köln: Brill (Brill’sStudies in Intellectual History 100).- Jacobi, K. (1995a), “Sprache und Wirklichkeit:Theorienbildung über Sprache im frühen 12. Jahrhundert”, in

Sten Ebbesen (ed.), Geschichte der Sprachteorie 3 Sprachtheorien inSpätantike und Mittelalter, Tübingen: Narr, 77-108 (in part. 96-100).- Jacobi, K. (1995b), “Natürliches Sprechen – Theoriesprache– Theologische Rede. Die Wissenshaftslehre des Gilbert vonPoitiers”, Zeitschrift für philosophische Forschung 49, 511-528.- Jacobi, K. (1996), “Einzelnes - Individuum - Person.Gilbert von Poitiers’ Philosophie des Individuellen”, in JanA. Aertsen and Andreas Speer (eds.), Individuum und Individualitätim Mittelalter, Berlin - New York: Walter de Gruyter, 3-21.- Jacobi, K. (1998), “Gilbert of Poitiers”, in RoutledgeEncyclopedia of Philosophy, vol. IV, ed. by Edward Craig, London-New York, 68-72.- Jacobi, K. (2002), “Philosophische und theologischeWeisheit. Gilbert von Poitiers’ Interpretation der ‘Regeln’des Boethius (De hebdomadibus)”, in Reiner Berndt, MatthiasLutz-Bachmann, Ralf M.W. Stammberger (eds.), “ Scientia ” und“ Disciplina ”. Wissenstheorie und Wissenschaftspraxis im 12. und 13.Jahrhundert, Berlin: Akademie Verlag, 71-78.- Jolivet, J. (1987), “Rhéthorique et théologie dans unepage de Gilbert de Poitiers ”, in Jean Jolivet and Alain deLibera (eds.), Gilbert de Poitiers et ses contemporains..., 183-198.Also in Id., Aspects de la pensée médiévale: Abélard. Doctrines du langage,Paris: Vrin, 1987, 293-310.- Jolivet, J. (1990), “Le jeu des sciences théorétiquesselon Gilbert de Poitiers”, in Simo Knuuttila, ReijoTyörinoja, and Sten Ebbesen (eds.), Knowledge and the Sciences inMedieval Philosophy. Proceedings of the Eighth International Congress ofMedieval Philosophy (SIEPM), Helsinki: Yliopistopaino, II, 71-88.- Jolivet, J. (1992a), “La question de la matière chezGilbert de Poitiers”, in Haijo Jan Westra (ed.), From Athensto Chartres. Neoplatonism and Medieval Thought. Studies in Honour of EdouardJeauneau, Leiden- New-York-Köln: Brill, 247-257.- Jolivet, J. (1992b), “Trois versions médiévales surl’universel et l’individu: Roscelin, Abélard, Gilbert de laPorrée”, Revue de métaphysique et de morale 97, 111-155.

- Jolivet, J. (1998), “Tournures et défaillances du dire.Trois textes du douzième siècle”, in Pierre Legendre (ed.),Du pouvoir de diviser les mots et les choses, Bruxelles: Maison dessciences de l’homme, 57-69.- Jolivet, J. and A. de Libera (eds.) (1987), Gilbert de Poitierset ses contemporains aux origines de la Logica Modernorum, Actes duseptième symposium européen d’histoire de la logique et de la sémantiquemédiévales, Poitiers 17-22 Juin 1985, Napoli: Bibliopolis.- Lewry, O. (1987), The Liber sex principiourm, a SupposedlyPorretanean Work. A Study in Ascription, in Jean Jolivet and Alain deLibera (eds.), Gilbert de Poitiers et ses contemporains..., 251-278.- Knuuttila, S. (1987), “Possibility and Necessity inGilbert of Poitiers”, in Jean Jolivet and Alain de Libera(eds.), Gilbert de Poitiers et ses contemporains...,199-218.- Knuuttila, S. (1993), Modalities in Medieval Philosophy, London-New York: Routledge, 75-82.- Maioli, B. (1974), Gli universali. Storia antologica del problema daSocrate al XII secolo, Roma: Bulzoni (in part. 302-348).- Maioli, B. (1979), Gilberto Porretano. Dalla grammatica speculativaalla metafisica del concreto, Roma: Bulzoni.- Marenbon, J. (1988), “Gilbert of Poitiers”, in PeterDronke (ed.), A History of Twelfth-Century Western Philosophy,Cambridge: Cambridge University Press, 328-352. - Marenbon, J. (1998), “The Twelfth Century”, in RoutledgeHistory of Philosophy, vol. III, ed. by John Marenbon, London,166-171.- Marenbon, J. (2002), “Gilbert of Poitiers and thePorretans on Mathematics in the Division of the Sciences”,in Reiner Berndt et al. (eds.), “ Scientia ” und “ Disciplina”…, 37-78.- Nielsen, L.O. (1976), “On the Doctrine of Logic andLanguage of Gilbert Porreta and His Followers”, Cahiers del’Institut du Moyen Age grec et latin 17, 40-69.

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Medieval logic and Semantics Leiden June 2008, Turnhout:Brepols (Artistarium, Supplementa). - Van Elswijk, H.C. (1966), Gilbert Porreta. Sa vie, son euvre, sapansée, Leuven: Université catholique de Louvain.- Vanni-Rovighi, S. (1956), “La filosofia di GilbertoPorretano ”, in Miscellanea del Centro di Studi Medievali LVIII,Milano: Vita e pensiero, 1-64; repr. in Ead., Studi di filosofiamedioevale I, Milano: Vita e pensiero, 1978.- Williams, M.E. (1951), The teaching of Gilbert Porreta on the Trinity asfound in his commentaries on Boethius, Roma: Università Gregoriana(Analecta Gregoriana LVI).