Despite Hegel himself drawing our attention to the habitual neglect of habit in the formation of the spirit, the concept of habit has remained generally unstudied in the Hegel scholarship. In this paper, I will present how the concept of habit holds several contradictory determinations in itself, and in so doing I will give an answer to the question of what motivates Hegel to cite habit as the hardest topic (am schwersten) to comprehend. By closely analyzing Hegel's account of habit in the Anthropology section of his Encyclopedia, I will reconstruct his account in thirteen contradictory pairs, which are the essential contradictions which make up Hegel's whole system. Specifically, Hegel defines habit as second nature which makes possible the transition from nature to Geist. The debate among Hegel commentators on the meaning of `second nature' reveals that to situate habit and second nature in Hegel's system means to determine the very character of Hegelian philosophy.