Kant claimed that there was no philosophy before the Critique of Pure Reason in 1781, and in 1806, Hegel declared that philosophy was now concluded. If both had been correct in their assertions, the history of philosophy, which we usually calculate to span two and a half millennia, would be reduced to 25 years. The 25 Years of Philosophy is an attempt to trace and understand the single idea that philosophy begins in 1781 and is concluded in 1806. It is not a contribution to the popular genre of the history of philosophy from Kant to Hegel; an overview of the era is not the goal. Instead, Eckart Förster examines the reasons that led Kant and Hegel to their statements, as well as the steps that could have taken place in such a short time from Kant's beginning to Hegel's end.