Experimental Philosophy of Science

Experimental philosophy of science gathers empirical data on how key scientific concepts are understood by particular scientific communities. In this paper we briefly describe two recent studies in experimental philosophy of biology, one investigating the concept of the gene, the other the concept of innateness. The use of experimental methods reveals facts about these concepts that would not be accessible using the traditional method of intuitions about possible cases. It also contributes to the study of conceptual change in science, which we understand as the result of a form of conceptual ecology, in which concepts become adapted to specific epistemic niches. 1. Experimental Methods and Conceptual Analysis Conceptual analysis is widely regarded as not merely one way to do philosophy, but as the method that defines philosophy itself. Philosophers have traditionally analyzed concepts by appealing to their own linguistic competence with the corresponding words. Effectively, the philosopher treats him or herself as a sociolinguistic ‘sample of one’. An analysis is judged adequate if the philosopher is unable to imagine a case in which their intuitions about the application of words clash with the implications of their analysis of the corresponding concepts. This approach can be extended to technical scientific concepts, such as the concept of the gene. Any philosopher of science worth their salt should be in a position to consult his or her intuitions as a scientifically literate sample of one, and thus equivalent for this purpose to a member of the scientific community. This traditional approach to conceptual analysis faces an obvious difficulty, however, if key scientific concepts, such as the gene concept, display substantial heterogeneity between different communities of researchers. A sample of one is obviously not going to reveal the differences in ideas about the gene which arise from different training, experience, or research focus. To study these differences it is necessary to sample various different groups of biologists. This rationale for adopting experimental methods in philosophy of science is reminiscent of the way in which the introduction of experimental methods in ethics and epistemology was necessary to 2 Experimental Philosophy of Science © 2008 The Authors Philosophy Compass 3 (2008): 10.1111/j.1747-9991.2008.00133.x Journal Compilation © 2008 Blackwell Publishing Ltd reveal cultural variation in ethical and epistemic concepts (Weinberg, Nichols, and Stich; Machery et al.). In our work we conceive scientific concepts as ongoing – and possibly ramifying – projects by scientific practitioners of deriving empirical generalizations of increasing scope and reliability. This is achieved by adjusting both the extension of those concepts, so as to encompass sets of instances with as much in common as possible, and the intension of those concepts, so that statements involving the category change their modal status in a way that reflects the centrality of those statements to current theory. For the scientific practitioner, concepts are tools which classify experience in ways that meet their specific needs and which are reshaped in the light of new empirical findings. This attitude is sometimes made explicit, but is implicit whenever scientists describe a statement as a ‘definition’ and yet regard it as hostage to future empirical findings, as they commonly do. If scientific concepts are evolving tools, it should not be the aim of philosophers of science to identify the one correct conception associated with a word or phrase. An alternative aim, and the one that we adopt, is to examine how conceptual differences reflect different scientific requirements. The needs of a particular group of investigators can be conceived as an epistemic ‘niche’ and changes in the concept over time can be seen as responses to changes in the niche. As a result of such conceptual evolution, what was originally a shared concept between two or more communities of researchers can become a range of related but distinct concepts. From this perspective, the conceptual analyst has no alternative but to examine what a range of different scientists say and do. But there are a number of ways to achieve this. One is via the history of science, an invaluable approach when a concept is changing over time. Another is by comparing published work from different scientific fields. A third is to conduct experimental studies that compare how scientists from different backgrounds respond to carefully chosen examples. This third method of ‘conceptual ecology’ has some disadvantages with respect to time, effort, and expense, and some advantages with respect to systematicity and rigor. In the next section we will give more substance to these remarks with specific examples of experimental work on the concept of the gene and the concept of innateness. The results of the innateness study reveal another strength of experimental philosophy when compared to traditional methods of conceptual analysis. Philosophers have long realized that many concepts are not applied on the basis of a single set of necessary and sufficient criteria. The idea that the instances of a concept may be related by ‘family resemblances’ is associated with Ludwig Wittgenstein. Conceptual analyses of this type postulate a cluster of criteria, some proportion of which must be satisfied for an instance to fall under the concept. However, we are not aware of philosophical analyses that assigns different weights to the various criteria that form such a cluster, or that consider the possibility