Plato and Platonism in Aristotle and the Aristotelian Tradition
No one would deny that individual cats resemble each other in many respects. All would presumably agree, as well, that cats are more similar to dogs than to bacteria or tennis games. Lastly, it seems natural to think that it is in virtue of the overall similarity between cats that we may say that they belong to one and the same species. All of this already hints that the notion of resemblance plays a crucial part on the epistemic level. It would underlie our classifications and taxonomies, help us identify natural regularities, and preside to analogic and inductive reasoning, amongst other cognitive functions.
This preeminent role of resemblance in ordinary and scientific discourse, clearly, appeals for a metaphysical explanation (Colwing 2017; Guigon 2009, 2014; Rodriguez-Pereyra, 2001, 2002). For many philosophers, our resemblance judgements ultimately depend of an intrinsic organization of reality. Realists, nominalists and trope theorists, however, have disagreed as to know whether resemblance facts concerning particulars should be explained in terms of shared properties. Similarity is also at forefront of discussions regarding natural kinds and essentialism, the issue being to know if it plays any explicative part in these matters. Resemblance even appears in the metaphysics of modality, as one may wish to account for counterfactual statements by devising a theory of “counterparts” which crucially relies on the notion of relative similarity (Lewis, 1986).
There is, in epistemology and philosophy of science, a direct echo to these discussions on the concept of resemblance. Following Goodman and Quine’s groundwork, issues relating to the justification of induction have sometimes been framed as problems of resemblance (Scheffler 1963, Hacking 1990, 1991). It is true that any inductive approach is related to the identification of regularities that are played out on the level of natural phenomena. It is up to scientists to identify those events which are repeated and therefore to define – if not build – a frame for their resemblance. Very often, scientists must make normative decisions – both practical and theoretical – about the type of resemblance that is relevant to a given context and discipline. But what to do with such decisions? Could they be made explicit? Are they unconscious or innate (Quine 1969)? Do they involve a degree of arbitrariness (Foucault 1969, Hacking 2002)? The same difficulty weighs on theories of confirmation. Indeed, the relationship between a hypothesis of nomological form and one of its empirical confirmations remains largely undetermined, as long as we are deprived of a clear concept of resemblance. Thus, it is often necessary to decide what constitutes an example, positive or negative, of any hypothesis (Elgin 2010). Even the concept of "scientific truth" seems to be understandable in terms of resemblance. As it appears, we may interpret our scientific theories as images or representations of the world (van Fraassen 1980). It is also advocated by some that theoretical models developed in science must be interpreted as approaching the truth (Peirce), or as being "sufficiently similar" to the thing to be described (Giere 2004, Godfrey-Smith, 2006, Elgin 2017). In both cases, a concept of resemblance is involved. Surely, the scientist will not give to these questions the same answers as the metaphysician – as she is more sensitive to the pragmatic dimension of many of these decisions.
Finally, the concept of resemblance is central to any account of representation and depiction. It has often been argued that resemblance is what differentiates descriptions and depictions, or languages and images. Unlike the relationship that is established between an image and its denotatum, a description does not look like what it describes. But what is the nature of this resemblance? To be sure, resemblance is not a sufficient condition of representation. But is it even a necessary condition (Goodman, 1968)? While it is clear that resemblance is a central concept of aesthetics, problems relating to its logical definition (symmetry, reflexivity, transitivity) resurface in the theories of depiction and representation. In this respect, Goodman’s position – that representation has nothing to do with any perceptual resemblance – is the most radical. But since the publication of Languages of Art, many philosophers have tried to amend this position in a way that makes it more compatible with common sense (Kulvicki 2006, Kulvicki 2014, McIver Lopes 1996, Blanc-Benon 2009).
There are, then, a great deal of issues surrounding the notion of resemblance in contemporary philosophy. Here are some of the questions we invite contributors to discuss in this thematic issue of Philosophia Scientiæ: are there forms and degrees of resemblance, or could one devise an encompassing or "cosmic" account of this concept? Does similarity between particulars, metaphysically speaking, simply consist in the fact that they share a number of properties? Is the relation of resemblance symmetrical? Is it reflexive? Is similarity, global or aspectual, based on objective facts? Is resemblance dispensable or eliminable? Do we have an innate intuition of resemblance? How to account for the "vague" character of resemblance? What role does similarity play on the epistemic level? Do we need a notion of similarity to account for our classifications and taxonomies, or to properly define biological, chemical, or natural "kinds”? Which role(s) does resemblance play in science? Does resemblance allow to define the notion of depiction?