This essay explicates and assesses Yeshayahu Leibowitz's axiology, and its relation to the value he claims halakhic practice instantiates: service of God. It argues that, while Leibowitz often affirms a relativist “polytheism of values,” he sometimes implies that the religious value is the “most valuable value.” However, this is not due to its material content, because serving God is objectively best; rather it is because, consonant with his negative theology, it most fully instantiates the formal properties of a value. The (...) essay concludes by assessing the tenability of Leibowitz's metaethics as well as the argument for positing this contentless value as an intention and reason for halakhic practice. (shrink)