Near the beginning of Beyond Good and Evil, Nietzsche writes that “psychology is once again the path to the fundamental problems” (BGE 23). This raises a number of questions. What are these “fundamental problems” that psychology helps us to answer? How exactly does psychology bear on philosophy? In this conference paper, I provide a partial answer to these questions by focusing upon the way in which psychology informs Nietzsche’s account of value. I argue that Nietzsche’s ethical theory is based upon the idea that power has a privileged normative status: power is the one value in terms of which all others values are to be assessed. If this is the correct interpretation of Nietzsche’s ethical theory, though, it raises a question: how could power have a privileged status, given that Nietzsche denies that there are any objective facts about what is valuable? I argue that Nietzsche’s account of psychology provides the answer: he grounds power’s privileged status in facts about the nature of human motivation. In particular, Nietzsche’s account of drives entails that human beings are ineluctably committed to valuing power. So Nietzsche’s ethical theory follows from his philosophical psychology.

Freud claimed that the concept of drive is "at once the most important and the most obscure element of psychological research." It is hard to think of a better proof of Freud's claim than the work of Nietzsche, which provides ample support for the idea that the drive concept is both tremendously important and terribly obscure.  Although Nietzsche's accounts of agency and value everywhere appeal to drives, the concept has not been adequately explicated.  I remedy this situation by providing an account of drives.  I argue that Nietzschean drives are dispositions that generate evaluative orientations, in part by affecting perceptual saliences.  In addition, I show that drive psychology has important implications for contemporary accounts of reflective agency.  Contemporary philosophers often endorse a claim that has its origins in Locke and Kant: self-conscious agents are capable of reflecting on and thereby achieving a distance from their motives; therefore, these motives do not determine what the agent will do.  Nietzsche's drive psychology shows that the inference in the preceding sentence is illegitimate.  The drive psychology articulates a way in which motives can determine the agent's action by influencing the course of the agent's reflective deliberations.  An agent who reflects on a motive and decides whether to act on it may, all the while, be surreptitiously guided by the very motive upon which he is reflecting.  I show how this point complicates traditional models of the role of reflection in agency.

A recurrent theme in Nietzsche's work is the idea that agents are in some sense ignorant of their own actions.  In this conference paper, I ask two questions: what exactly does Nietzsche mean by this claim, and how would the truth of this claim affect philosophical models of agency? I argue that Nietzsche's claim about self-ignorance is intended to draw attention to the fact that there are influences upon reflective episodes of choice that have three features.  First, these influences are pervasive, occurring in every episode of choice.  Second, these influences are normatively significant, in that their presence typically affects the outcome of deliberation. Third, these influences are difficult to detect, in that one needs to acquire a great deal of self-knowledge in order to begin to counteract their effects.  I briefly sketch the way in which these claims follow from Nietzsche's philosophical psychology.