For the Parmenidean monist, there are no distinctions whatsoever-indeed, distinctions are unintelligible. In The Parmenidean Ascent, Michael Della Rocca aims to revive this controversial approach on rationalist grounds. He not only defends the attribution of such an extreme monism to the pre-Socratic philosopher Parmenides, but also embraces this extreme monism in its own right and expands these monistic results to many of the most crucial areas of philosophy, including being, action, knowledge, meaning, truth, and metaphysical explanation. On Della Rocca''s account, there is no differentiated being, no differentiated action, knowledge, or meaning; rather all is being, just as all is action, all is knowledge, all is meaning. Motivating this argument is a detailed survey of the failure of leading positions (both historical and contemporary) to meet a demand for the explanation of a given phenomenon, together with a powerful, original version of a Bradleyan argument against the reality o