The article presents Vittorio Possenti's philosophical thought concerning nihilism. The Italian philosopher first shows the different varieties of nihilism and provides a more in-depth analysis of theoretical and practical nihilism. Theoretical nihilism has its origin in the depravity of theoretical reason and the modern rejection of classical metaphysics. Every variety of nihilism has its root in speculative nihilism. The basis of practical nihilism is the depravity of practical reason. The consequence of this is an erroneous perception of human freedom and rejection of the idea of the good as the supreme ethical category. In practical nihilism there is also no place for the concept of natural law. On the ground thus formed, legal and political nihilism arises in a social context.