 Recent work on this issue tends to defend one of the following three answers to this question: contractualism, consequentialism, or constitutivism. The contractualist says that a particular cognitive state counts as a kind of success because the practice of so counting it serves certain widely held practical interests. For instance, according to Craig (1990), we describe a person as “knowing” something as a way of signaling that her testimony with respect to that thing is to be trusted. The consequentialist says that a particular cognitive state counts as a kind of success because it tends to constitute or tends to promote some crucial benefit. According to some consequentialists, the benefit in question is that of having true beliefs and lacking false beliefs (see BonJour 1985, Audi 1993). According to others, it is the benefit of having a comprehensive understanding of reality. According to others, it is a benefit that is not narrowly epistemic, e.g., living a good life, or being an effective agent, or spreading one’s gene pool. Finally, the constitutivist may say that a particular cognitive state counts as a kind of success if it is the constitutive aim of some feature of our lives to achieve that state (see Korsgaard 2009 for a defense of constitutivism concerning norms of rationality). For instance, the constitutivist might say that knowledge is a kind of cognitive success by virtue of being the constitutive aim of belief, or that understanding is a kind of cognitive success by virtue of being the constitutive aim of reasoning, or that practical wisdom is a kind of cognitive success by virtue of being the constitutive aim of all human activity. Of course, there are philosophers who count as “constitutivists” by virtue of thinking, say, that knowledge is the constitutive aim of belief—but these same philosophers are not thereby committed to the constitutivism described here, since they are not committed to this explanation of what makes knowledge a kind of cognitive success.