This article discusses the purpose of Fichte of an “applied philosophy” aimed at reflecting the relationship between philosophical thinking (speculation) and the external reality to philosophy (life). The analysis focuses on the so-called Doctrine of the State (1813). The text is divided into four sections: 1) about the relationship between system and critique, 2) between system and self-critique, 3) between system and life and, finally, 4) between pure and applied philosophy. It is argued that the philosophical legacy of the last Fichte consists of the vital validation of knowledge.