 This view, which, following Williams (2006), we will call “humanist,” has two variants. The first, per Mulhall, is linguistic or conceptual, influenced by Wittgenstein (1958). We come to understand notions like thinking, deciding, and feeling in terms of the behavior of other human beings, and, although we can attribute some of these capacities or states to other beings, it is only by extension or analogy (Hanfling 2001). We also learn the appropriate ways of acting toward fellow human beings in learning the very concept: for example, human beings are to be named, and not eaten even when they are dead. We do not conclude that human beings must be treated this way; the recognition that they must is already part of the meaning of the concept (Diamond 1978; Gleeson  2008).[13]  This “thick” concept of human being is not a biological one, and need not have the same extension as the class of Homo  sapiens[14].  For some humanists of this type, a newly-created embryo is not a human being, and it is not part of the meaning of human being that the life of a newly-fertilized embryo must be protected to the same extent as the life of a newborn human infant (Crary 2007). But the very fact that other humanists do regard early embryos as human beings suggests the need for an account of how such a deeply-embedded concept can be so vague or debatable at the margins.