In this paper I will examine the relationship between the philosophies of Vailati and Peirce on hypothetical reasoning. In this way I will try to show that Vailati was more aware of pragmatism than his commentators thought. But, on the other hand, I will try also to point out the crucial differences between his thought and the original American one. The interest to this reconstruction is not only philological. I would like to suggests that in this epoch in which we are watching at a true pragmatic turn in philosophy Vailati can be very important for both his way of understanding (or misunderstanding) pragmatism and the peculiar rational needs – the importance of genealogy in science and free will – he addressed to every formulation of pragmatism.