A metalevel problem for animal rights theory

In this paper I argue that a leading form of animal rights theory is vulnerable to a fundamental logical inconsistency. The inconsistency takes the form of the well-known “inconsistent triad” problem: three principles that appear sound in isolation, when combined in a single theory, are logically incompatible, thus, rendering the theory as logically unstable. The three incompatible principles that are constitutive of the relevant form of animal rights theory are: the psychology or sentience principle (hereafter, the psychology principle); the same kind or equality principle (hereafter, the same kind principle) and the evolution or genomic plasticity principle (hereafter, the evolution principle). For the purposes of the following analysis, by “animal rights theory” I mean to refer to theories in which particular moral ‘goods’, such as utility-trumping rights or the principle of equal consideration of interests, are extended to nonhuman animals on the grounds of sentience or, strictly speaking, the possession of a psychology above a threshold level of complexity marked by sentience. Accordingly, the target animal rights theories are “naturalistic” theories, that is, they identify or analyse evaluative properties (intrinsic value, inherent value, moral considerability, etc.) as natural properties, specifically, psychology or sentience. Notable examples of animal rights theorists who presuppose meta-ethical naturalism and, if the argument to follow is sound, are vulnerable to the inconsistent triad problem include Peter Singer, Tom Regan, Gary Francione, David DeGrazia, Mark Rowlands, Julian H. Franklin, Evelyn Pluhar, Gary Varner, Alasdair Cochrane, Robert Garner, Will Kymlicka, indeed, most animal rights theorists who write in the so-called analytic tradition.