This book examines nature as a foundational concept for political and constitutional theory, drawing on readings from Plato and Hegel to counter the view that optimal political arrangements are determined by nature. Focusing on the dialectical implications of the word ‘nature’, i.e. how it encompasses a range of meanings stretching up to the opposites of sensuousness and ideality, the book explores the various junctures at which nature and politics interlock in the philosophies of Plato and Hegel. Appearance and essence, inner life and public realm, the psychical and the political are all shown to be parts of a conflictual structure that requires both infinite proximity and irreducible distance. The book offers innovative interpretations of a number of key texts by Plato and Hegel to highlight the metaphysical and political implications of nature’s dialectical structure, and re-appraises their thinking of nature in a way that both respects and goes beyond their intentions.