An influential species of evolutionary debunking argument against moral realism holds that since cumulative natural selection shaped the contents of our moral beliefs, those beliefs do not count as knowledge. Critics have taken issue with a range of empirical, epistemic, and metaphysical assumptions that EDAs are said to rely on, which has engendered a complex debate over whether and to what extent the debunking challenge succeeds. However, recently it has been argued that we can reject EDAs without having to enter (...) this thicket of issues. EDAs supposedly fail at the outset, by trading on a glaring misunderstanding about the scope of natural selection explanations. I argue that this objection to EDAs fails, and itself rests on a mistaken view of natural selection explanation and its relation to justification. (shrink)

One approach to assess the explanatory power of natural selection is to ask what type of facts it can explain. The standard list of explananda includes facts like trait frequencies or the survival of particular organisms. Here, I argue that this list is incomplete: natural selection can also explain a specific kind of individual-level fact that involves traits. The ability of selection to explain this sort of fact vindicates the explanatory commitments of empirical studies on microevolution. Trait facts must be (...) distinguished from a closely related kind of fact, that is, the fact that a particular individual x has one trait rather than another. Whether or not selection can explain the latter type of fact is highly controversial. According to the so-called ‘Negative View’ it cannot be explained by selection. I defend the Negative View against Nanay’s objection. (shrink)

The explanatory role of natural selection is one of the long-term debates in evolutionary biology. Nevertheless, the consensus has been slippery because conceptual confusions and the absence of a unified, formal causal model that integrates different explanatory scopes of natural selection. In this study we attempt to examine two questions: (i) What can the theory of natural selection explain? and (ii) Is there a causal or explanatory model that integrates all natural selection explananda? For the first question, we argue that (...) five explananda have been assigned to the theory of natural selection and that four of them may be actually considered explananda of natural selection. For the second question, we claim that a probabilistic conception of causality and the statistical relevance concept of explanation are both good models for understanding the explanatory role of natural selection. We review the biological and philosophical disputes about the explanatory role of natural selection and formalize some explananda in probabilistic terms using classical results from population genetics. Most of these explananda have been discussed in philosophical terms but some of them have been mixed up and confused. We analyze and set the limits of these problems. (shrink)

I have recently argued that origin essentialism regarding individual organisms entails that natural selection does not explain why individual organisms have the traits that they do. This paper defends this and related theses against Mohan Matthen's recent objections.

Does natural selection explain why individual organisms have the traits that they do? According to "the Negative View," natural selection does not explain why any individual organism has the traits that it does. According to "the Positive View," natural selection at least sometimes does explain why an individual organism has the traits that it does. In this paper, I argue that recent arguments for the Positive View fail in virtue of running afoul of the doctrine of origin essentialism and I (...) demonstrate that other recent defenses of the Negative View depend upon my own for their plausibility. (shrink)

The concept of population thinking was introduced by Ernst Mayr as the right way of thinking about the biological domain, but it is difficult to find an interpretation of this notion that is both unproblematic and does the theoretical work it was intended to do. I argue that, properly conceived, Mayr’s population thinking is a version of trope nominalism: the view that biological property-types do not exist or at least they play no explanatory role. Further, although population thinking has been (...) traditionally used to argue against essentialism about biological kinds, recently it has been suggested that it may be consistent with at least some forms of essentialism—ones that construe essential properties as relational. I argue that if population thinking is a version of trope nominalism, then, as Mayr originally claimed, it rules out any version of essentialism about biological kinds. (shrink)

One of the most influential arguments against the claim that computers can think is that while our intentionality is intrinsic, that of computers is derived: it is parasitic on the intentionality of the programmer who designed the computer-program. Daniel Dennett chose a surprising strategy for arguing against this asymmetry: instead of denying that the intentionality of computers is derived, he endeavours to argue that human intentionality is derived too. I intend to examine that biological plausibility of Dennett’s suggestion and show (...) that Dennett’s argument for the claim that human intentionality is derived because it was designed by natural selection is based on the misunderstanding of how natural selection works. (shrink)

Many moral philosophers accept the Debunking Thesis, according to which facts about natural selection provide debunking explanations for certain of our moral beliefs. I argue that philosophers who accept the Debunking Thesis beg important questions in the philosophy of biology. They assume that past selection can explain why you or I hold certain of the moral beliefs we do. A position advanced by many prominent philosophers of biology implies that this assumption is false. According to the Negative View, natural selection (...) cannot explain the traits of individuals. Hence, facts about past selection cannot provide debunking explanations for any of our moral beliefs. The aim of this paper is to explore the conflict between the Debunking Thesis and the Negative View. (shrink)

The “negative view” is the claim that natural selection cannot explain why a particular individual has one trait, rather than another. Here, I modify an example from Lewens (2001) to show that this claim is sometimes false. I then advance a variation on the negative view. It is the claim that selection at the organism level within a lineage cannot explain why a particular individual in that lineage has one allele, rather than another. This formulation better describes the explanatory role (...) of selection. (shrink)

The “negative view” is the claim that natural selection cannot explain why a particular individual has one trait, rather than another. Here, I modify an example from Lewens to show that this claim is sometimes false. I then advance a variation on the negative view. It is the claim that selection at the organism level within a lineage cannot explain why a particular individual in that lineage has one allele, rather than another. This formulation better describes the explanatory role of (...) selection. (shrink)

There are ongoing debates in philosophy of biology about what falls within natural selection's explanatory scope. These include debates about whether selection can explain individual-level traits, the extent to which selection can explain distributions of trait frequencies, and whether selection can explain the origin of novel traits. Here I'll survey these debates, suggest which views seem most plausible, and describe some useful conceptual frameworks for thinking about the issues involved.

Sound like a philosopher’s controversy? I think so. In ‘Evolution,’ I argued that Anti-Individualism was committed to a ‘highly metaphysical’ proposition at odds with the methodology of population genetics. This infelicity gave me reason for rejecting it. In his recent article, Pust takes issue with Neander and me. Until Pust wrote, Sober felt some small pressure from Individualism, and had shifted, albeit microscopically, toward it—he thought that on a very broad conception of causation, there might be some reason to think (...) that selection explains individual traits. He is now convinced that he was right all along. So we are back where we were a few years ago, though with new arguments on each side. Such is the nature of progress in philosophy. The purpose of this paper is to offer some refinements of Individualism. (shrink)

It has been claimed that certain forms of individual essentialism render the Theory of Natural Selection unable to explain why any given individual has the traits it does. Here, three reasons are offered why the Theory ought to ignore these forms of essentialism. First, the trait-distributions explained by population genetics supervene on individual-level causal links, and thus selection must have individual-level effects. Second, even if there are individuals that possess thick essences, they lie outside the domain of the Theory. Finally, (...) the contingency of sexual reproduction suggests that essentialism is misguided in this arena. 1 The problem 2 A reprise of the controversy 3 Enter individual essences 4 How can selection not have individual-level effects? 5 Why can't we get rid of essences we don't like? 6 Is sex necessary? (shrink)

A long-running dispute concerns which adaptation-related explananda natural selection can be said to explain. At issue are explananda of the form: why a given individual organism has a given adaptation rather than that same individual having another trait. It is broadly agreed that one must be ready to back up a “no” answer with an appropriate theory of trans-world identity for individuals. I argue, against the conventional wisdom, that the same is true for a “yes” answer. My conclusion recasts the (...) landscape and opens the door to a potential resolution. (shrink)

There is a substantial literature on evolutionary debunking arguments (EDAs) in metaethics. According to these arguments, evolutionary explanations of our moral beliefs pose a significant problem for moral realism, specifically by committing the realist to an unattractive pessimism about the prospects of our having moral knowledge. In this paper, I argue that EDAs exploit an equivocation between two distinct readings of their central claim. One is plausibly true but has no epistemic relevance, and the other would have epistemic consequences for (...) realism, but is false. If I'm right, this undermines attempts to use evolutionary explanations to debunk belief in other domains too. (shrink)

Can selection explain why individuals have the traits they do? This question has generated significant controversy. I will argue that the debate encompasses two separable aspects, to detrimental effect: (1) the role of selection in explaining the origin and evolution of biological traits and (2) the implications this may have for explaining why individuals have the traits they do. (1) can be settled on the basis of evolutionary theory while (2) requires additional, extra-scientific assumptions. By making a distinction between traits (...) affected by a single factor and traits affected by multiple factors I show that selection can, under certain conditions, help explain the origin of traits. Resolving the first aspect enables us to critically assess the various incompatible and independent philosophical commitments made within the second aspect of the debate. (shrink)

An influential argument due to Elliott Sober, subsequently strengthened by Denis Walsh and Joel Pust, moves from plausible premises to the bold conclusion that natural selection cannot explain the traits of individual organisms. If the argument were sound, the explanatory scope of selection would depend, surprisingly, on metaphysical considerations concerning origin essentialism. I show that the Sober-Walsh-Pust argument rests on a flawed counterfactual criterion for explanatory relevance. I further show that a more defensible criterion for explanatory relevance recently proposed by (...) Michael Strevens lends support to the view that natural selection can be relevant to the explanation of individual traits. (shrink)

Ruth Millikan and others advocate theories which attempt to naturalize wide mental content (e.g. beliefs.