William James's doctrine of the will to believe is one of the most infamous arguments in modern philosophy. Critics frequently interpret it as a feeble defense of wishful thinking. Such criticisms rely on treating James's ethics of belief independently from his moral psychology. Unfortunately, this separation is also implicitly assumed by many of his defenders. James's ethics of willing, I here show, relies on his robust psychology of the will. In his 1896 essay, "The Will to Believe," James carefully circumscribes those situations in which willful belief is defensible in a way that closely matches his description of decision by effort in the "Will" chapter of his 1890 The Principles of Psychology. Explicating this match helps show why the will to believe is not a defense of wishful thinking, but rather a naturalistic account of the value of sculpting our habits, or of what I describe as Jamesian self-transformation.