The question on the essence of man and his relationship to nature is certainly one of the most important themes in the philosophy of Hans Jonas. One of the ways by which Jonas approaches the issue consists in a comparison between the contemporary interpretation of man and forms of wisdom such as those conveyed by ancient Greek philosophy and the Jewish tradition. The reconstruction and discussion of these frameworks play a fundamental role in Jonas’s critique of the modern mind. In the first section I introduce the anthropological problem in Hans Jonas’s oeuvre. Moreover, I clarify why it becomes essential for Jonas to resort to different forms of traditional wisdom. In the second and third sections I try to give an account (as complete as possible) of the two generalisations which Jonas shapes in order to criticise the modern concepts of man and nature. In the last section I show how Jonas links these generalisations to his own philosophical assessment of modernity. Finally, I focus on his methodology, which exemplifies how critical thinking may arise from a reconsideration of traditional contents