William James's "The Will to Believe" and the Ethics of Self-experimentation

William James's "The Will to Believe" has been criticized for offering untenable arguments in support of belief in unvalidated hypotheses. Although James is no longer accused of suggesting we can create belief ex nihilo, critics continue to charge that James's defense of belief in what he called the "religious hypothesis" confuses belief with hypothesis adoption and endorses willful persistence in unvalidated beliefs—not, as he claimed, in pursuit of truth, but merely to avoid the emotional stress of abandoning them. I argue that James's position in "The Will to Believe" can be defended provided we give up thinking of it as ethics of belief and think of it instead as an ethics of self-experimentation. Subjective data (including wants, needs, and desires) are relevant to rational consent to participation in research.