La Prudence chez Aristote is one of the most important contributions of the Aristotelian literature of the twentieth century, and undoubtedly among those that have aroused vast debate on his work. If Aristotle knows the ethical intellectualism of Socratic matrix (evoked in the beginning of Nicomachean Ethics), he goes far beyond. Among the most salient points of the work of Aubenque there is the interpretation of Aristotelian ethics in terms of "existential intellectualism": the uncertainty, the incompleteness of the sublunar world make the intervention of the individual phrónesis decisive (the term is translated by the author with prudence, on the basis of the Ciceronian terminology). The virtue then springs from the role and choice of man in relation to the various and changing conditions of reality, rather than from the ideal (Platonic) definition of virtuous behavior. Investigating the relationships between metaphysics, cosmology and ethics, Aubenque provides a renewed and convincing interpretation of the moral reflection of Aristotle.