recognized again as the queen of the sciences.” While one might cast a dubious glance at the “again,” many of Nietzsche’s insights were indeed psychological, and many of his arguments invoke psychological premises. In Genealogy, he criticizes the “English psychologists” for the “inherent psychological absurdity” of their theory of the origin of good and bad, pointing out the implausibility of the claim that the utility of unegoistic
actions would be forgotten. Tabling whether this criticism is valid, we see Nietzsche’s methodological naturalism here: moral claims should be grounded in empirical psychological claims. Later in Genealogy, Nietzsche advances his own naturalistic account of the origins of good, bad, and evil.
Three cheers for methodological naturalism, but it was not Nietzsche’s innovation, and he did not pioneer its application to morality. The list of moral naturalists who appealed to psychology arguably includes Aristotle, Descartes, Spinoza, Bentham, and Mill, among many others. If Nietzsche’s naturalism is to be worth the candle of contemporary scholarship, it must involve more than the methodological naturalism that predated him by centuries and to which he made no serious contribution. Nietzsche’s key contribution to naturalism is not his adherence to its methodology, but his discovery of certain psychological facts. In particular, he realized that mental states are not ordinary dyadic relations between a subject and an intentional content. Nietzsche discovered the tenacity of intentional states: when an intentional state loses its object (because the subject realizes the object does not exist, because the object is forbidden, or because of something else), a new object replaces the original; the state does not disappear entirely. As Nietzsche puts it Genealogy, “Man would rather will the void than be void of will.” Nietzsche relies on the tenacity thesis in his explanation of the origin of bad conscience: “All instincts that do not discharge themselves outwardly turn inward […. They turn] against [their] possessors.” When hostility towards others becomes impossible, hostility does not disappear; instead, its object is replaced.