Abstract

Jean Baptiste van Helmont (Bruxelles, 1578-1644) attributed to himself the title of "Philosphus per ignem". Philosophy "per ignem" has a relevant place in XVII century experimental medicine because of its combination of mystic-scientific and scientific-experimental thought. The Helmontian therapy, which implicitly questions the effectiveness of the theory of the humours and the correctness of Aristotelian and Galenical theories followed by the medical orthodoxy, was opposed by the ecclesiastical censorship. His medical-theological hypotheses, which we can ascribe to a mystical-hermetic tradition connected to neo-platonic culture and to alchemy, led Helmont to be condemned by the Inquisition and to be rejected by the scientific community, which did not accept the existence of an invisible vital and natural force.