Are debunking arguments internally coherent?

Abstract

In her ‘A Darwinian Dilemma for Realist Theories of Value’, Sharon Street argues that realist theories of morality in metaethics are not compatible with contemporary science, specifically not with the theory of evolution. In the following years a growing amount of articles emerged, many of which replied to Street’s argument. In this paper, I will defend Street’s evolutionary debunking argument (EDA) against recent criticism. In this thesis, I will review whether Street’s EDA is internally coherent. In particular, critics of Street’s EDA have argued that her argument is internally incoherent in two ways. Firstly, Street’s EDA is said to overgeneralize to forms of knowledge which are necessary for her argument to debunk moral beliefs. This argument is called the epistemic incoherence objection. Secondly, it is claimed that Street’s EDA cannot undermine moral beliefs, as the argument is itself dependent on substantial moral claims. This is the objection of self-defeat. The main question I will address in this thesis is whether the epistemic incoherence objection and the objection of self-defeat succeed in showing that Street’s EDA is internally unstable.