The Philosophy of Science (and of Life) of Donald T. Campbell

MELVIN M. MARK

Cousin to the amoeba, how can we know for certain?

This was one of Don Campbell’s “slogans,” as he called them. Pithy-or sometimes unwieldy-phrases that he used to consolidate and communicate a complex philosophical or methodological issue. “Cousin to the amoeba, how can we know for certain?’ This is my favorite of Campbell’s slogans, and a fitting one to highlight in dis- cussing his philosophy of science. Of course, a brief paper cannot do justice to Campbell’s work in this area. Nor is it possible to explore in detail the relationship between Campbell’s efforts in the philosophy of science and his scholarship on knowledge processes in other domains, such as bias in social perception, intergroup stereotyping, visual illusion, measurement, research design and validity, and evaluation (Shadish, Cook, & Leviton, 1991). But Campbell’s “amoeba” slogan provides us a synoptic view of his philosophy of science.

Campbell was a realist-he believed that there exists an external reality, that all is not simply subjective construction. But he was certainly not a naive realist; he did not believe in direct access to that external reality. As with the slogan cited above, he made this point often and clearly: for example, “all knowing is highly presumptive, involving presumptions not directly or logically justifiable” (Campbell, 1969, p. 66). Although it is indirect, Campbell did not believe that knowledge about the world is independenr of our experience with it. As he said, “Evolutionary epistemology has in it an unproven assumption of a real world external to the organism, with which the organism is in dialectic interaction” (Campbell, 1984, p. 30, ital- ics added).

The absence of direct knowing about the world did not lead Campbell to despair about scientific or everyday knowledge processes. Instead, he emphasized the “trust-doubt ratio” (e.g., Campbell, 1984), which specifies that we “trust most of our current beliefs while we use that distributed fulcrum to revise a few of them” (Campbell, 1984, p. 29). Campbell frequently cited Quine and his reference to Neurath’s metaphor of a boat needing repair while at sea. “In

Melvin M. Mark l Department of Psychology, Penn State, University Park, PA, 16802. E-Mail, MSM@PSU.EDU.

American Journal of Evaluation, Vol. 19, No. 3, 1998, pp. 399-402. All rights of reproduction in any form reserved. ISSN: 1098-2140 Copyright 0 1998 by American Evaluation Association.

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science we are like sailors who must repair a rotting ship while it is afloat at sea. We depend on the relative soundness of all other planks while we replace a particularly weak one. Each of the planks we now depend on we will in turn have to replace. No one of them is a founda- tion, nor point of certainty, no one of them is incorrigible” (Campbell, 1969, p. 43). As an aside, in one of his less successful slogans, Campbell described this concept with the term “omnifallibilist trust” (Cook & Campbell, 1986; Campbell, 1991).

The critical realism in Campbell’s philosophy of science leads directly in his methodol- ogy to such approaches as triangulation, the multitrait-multimethod matrix, validity threats and strategies for ruling out plausible rival hypotheses. The purpose of these techniques, according to Campbell, is to winnow out some hypotheses, in a Popperian falsification.

The tentative retention of some hypothesis-tentative given the fallibility of our observa- tions and the possibility of future disconfirmations-is an important aspect of Campbell’s evolutionary epistemology. Campbell developed a descriptive epistemology, designed to account for how we actually do learn about the world (Campbell, 1977). Campbell’s evolu- tionary epistemology is based on the following analogy with evolutionary theory: (1) blind variations-say, novel hypotheses or social programs-are identified or developed; (2) these variations are subjected to selection processes -such as an experimental test; and (3) the selected variations are retained and perhaps further propagated-such as through funding decisions and publication and dissemination of results (Campbell, 1974).

Space and other limitations do not allow a thorough review of Campbell’s evolutionary epistemology, or indeed of other aspects of his philosophy of science. Nor is this the setting to review the criticisms that have been made about the applicability of this approach to the field of evaluation (see Dunn, 1982; Shadish, et al., 1991, pp. 157-160). Suffice it to say that Camp- bell’s evolutionary epistemology is a highly impressive intellectual achievement. Karl Pop- per, the famed philosopher of science, in commenting on Campbell’s contribution to a 1974 volume on Popper’s philosophy, wrote: “Professor Campbell’s remarkable contribution is perhaps the one which shows the greatest agreement with my epistemology, and (what he can- not know) an astonishing anticipation of some things which I had not yet published when he wrote his paper. In addition, it is a treatise of prodigious historical learning: there is scarcely anything in the whole of modem epistemology to compare with it” (Popper, 1974, p. 1059).

Intertwined with Campbell’s philosophy of science was his sociology of science. Camp- bell recognized that science is a social process, and that scientists are affected by human moti- vations other than the search for truth. His sociology of science, combined with his evolutionary epistemology, led him to suggest a set of mechanisms that could facilitate truth seeking in the evaluation community; these are summarized in his 1984 paper, “Can we be scientific in applied social science?’

Campbell wanted science, and evaluation, to keep the goal of truth (Campbell, 1984). Further, he believed that our goal should be truth as defined in terms of correspondence-that is, that validity consists of the correspondence between our inferences, on the one hand, and the actual state of reality, on the other (Campbell, 1977). At the same time, as he acknowl- edged, his epistemology indicates that this goal is unattainable (Campbell, 1991). Thus, he said, “we accept a . . . surrogate goal of increasing coherence even if we regard this as merely our best available approximation of the truth” (Campbell, 1991, p. 589). Coherence can be increased through such familiar Campbellian strategies as identifying and ruling out plausible rival hypotheses and pattern matching.

Campbell’s epistemology emphasized patterns and pattern matching in drawing infer- ences (Campbell, 1966). His emphasis on patterns also shows up early in his substantive work,

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such as his 1950 definition of attitudes, which emphasized “consistency in response” to objects as evidence of one’s attitude toward the object (Campbell, 1950, p. 3 1). Fitting of the pattern matching theme in Campbell’s work, a pattern may emerge across this set of papers that will sketch Don Campbell the man as well as Donald T. Campbell the scholar. I offer a few observations linked to his theory of knowledge.

Campbell’s modesty is almost legendary. His writings often include self-deprecating comments, apologies, and calls for help, as exemplified by the following quotes: “I am not scholar enough to answer definitively” (Campbell, 1969, p. 46)-a comment followed, by the way, by what is probably the best answer to the question in the literature; “The problem is turned over to you unfinished and inadequately formalized” (Campbell, 1984, p. 44)-a com- ment that follows, by the way, an elegant explication of the problem and an incisive set of sug- gested improvements; “I feel sure that in the vast literature there are many other hermeneutic principles, but I do not recollect encountering such a list. (This is a request for help.)” (Camp- bell, 1991, p. 589). Although I do not have the evidence that warrants a causal assertion (this is a request for help), there may be a relationship between Campbell’s characteristic modesty and his epistemology-his belief that all knowledge claims are inherently presumptive. “Cousin to the amoeba, how can we know for certain?”

Campbell’s modesty was also linked to his graciousness and support for students and col- leagues, even colleagues he did not know. Chip Reichardt (1996) recounts Campbell’s ten- dency to tell students or colleagues who were having doubt about their work about his own uncertainties or his difficulty with publishing a particular classic paper. Also, Campbell often described some graduate student as “our resident expert” on a particular topic, referring others to that student for advice. The result of course was that the student became an expert on the

topic. It seems fitting that Campbell, who studied the evolutionary and social bases of helping (Campbell, 1972), would be so gracious and helpful to his intellectual family.

And Campbell was equally gracious to his critics. He distributed with his papers the pub- lished criticisms of them. He invited critics to campus for discussion and to meet with his stu- dents. And of course he was a keen critic of his own work. Later papers are filled with

revisions of earlier ones and with discussion of their unanticipated consequences (see, e.g.,

Campbell & Boruch, 1975, pp 202-203). This self-criticism and welcoming of other critics

was most fitting from a man who argued for a “mutually monitoring, disputatious community

of scholars” (Campbell, 1984, p. 44)-another loquacious slogan.

“Cousin to the amoeba, how can we know for certain?’ Those who knew Don Campbell know with all the certainty allowed to humans just how special he was.

REFERENCES

Campbell, D. T. (1950). The indirect assessment of social attitudes. Psychological Bulletin, 47, 15-38.

Campbell, D. T. (1966). Pattern matching as an essential in distal knowing. In K. R. Hammond (Ed.),

The psychology of Egon Brunswik (pp. 8 1- 106). New York: Holt, Rinehart & Winston.

Campbell, D. T. (1969). A phenomonology of the other one: corrigible, hypothetical, and critical. In T. Mischel (Ed.), Human action: Conceptual and empirical issues. New York: Academic Press.

Campbell, D. T. (1972). On the genetics of altruism and the counter-hedonic components in human cul- ture. Journal of Social Issues, 28,2 l-37.

Campbell, D. T. (1974). Evolutionary epistemology. In P. A. Schilpp (Ed.), The philosophy of Karl Pop- per (pp.413-463). La Salle, IL: Open Court.

AMERICAN JOURNAL OF EVALUATION, 19(3), 1998

Campbell, D. T. (1977). Descriptive epistemology: Psychological, sociological, and evolutionary. Wil- liam James Lectures, Harvard University.

Campbell, D. T. (1984). Can we be scientific in applied social science? In R. F. Connor, D. G. Altman, & C. Jackson (Eds.), Evaluation studies review annual (Vol. 9, pp. 26-48). Newbury Park, CA: Sage.

Campbell, D. T. (1991). Coherentist empiricism, hermeneutics, and the commensurability of paradigms. International Journal of Educational Research, 15,587-597.

Campbell, D. T. & Boruch, R. (1975). Making the case for randomized assignment to treatments by con- sidering the alternatives: Six ways in which quasi-experimental evaluations in compensatory edu- cation tend to underestimate effects. In C. A. Bennett & A. A. Lumsdaine (Eds.), Evaluation and experiments: Some critical issues in assessing social programs (pp. 195-296). New York: Aca- demic Press.

Cook, T. D., & Campbell, D. T. (1986). The causal assumptions of quasi-experimental practice. Syn- these, 68, 141-180.

Dunn, W. N. (1982). Reforms as arguments. Knowledge: Creation, difision, utilization, 3,293-326. Popper, K. (1974). Replies to my critics: Campbell on the evolutionary theory of knowledge. In P. A.

Schilpp (Ed.), The philosophy of Karl Popper. (pp. 1059-1065. La Salle, III.: Open Court Publish- ing.

Reichardt, C. S. (1996). Obituary for Donald T. Campbell. Evaluation Practice, 17,3-5. Shadish, W. R., Cook, T. D., & Leviton, L. C., (1991). Foundations ofprogram evaluation: Theories of

practice. Newbury Park, CA: Sage.