Abstract
According to the theory of intrinsic value and moral standing known as the “substance view,” all human beings have intrinsic value, full moral standing and, with these, a right to life. The substance view has been defended by numerous contemporary philosophers who use the theory to argue that the standard human fetus has a right to life and, ultimately, that abortion is prima facie seriously wrong. In this paper, I identify three important errors committed by some of these philosophers in their defense of the theory---what I refer to as the “extratheoretical-proposition error,” “quantitative-differences error,” and “non-normative-answer error”---and conclude that these errors render their defense inadequate.