This book provides a new account of how Nietzsche's experimentalism informs his critical engagement with philosophical methodology. The book also demonstrates how Nietzsche's experimentalism allows for constructive responses to contemporary problems in the philosophy of science and of mind, including the realism-antirealism debate, the status of thought experiments, neuroscience and reductionism, and reconciliation of first- and third-person accounts of mind. In so doing, Nietzsche's method gets more accessible to philosophers of science and mind who are unfamiliar with his work.