  However, Descartes also provided Regius with philosophical arguments in reply to Voetius. He outlined a number of reasons why they were jointly opposed to describing the human mind as a substantial form. To say that human beings think because they have a ‘thinking form’ explains nothing; secondly, those who postulate the existence of substantial forms are unable to say more precisely what they are, and thus they appeal to ‘occult’ realities that they do not understand; and, perhaps most importantly, if the alleged substantial forms of other natural phenomena were made redundant by  developments in physics, there would be a danger that the spirituality of the mind or soul would be compromised by similar advances in the sciences.  “All the arguments that are used to prove substantial forms may be applied to the form of a clock, although no one claims that it is substantial” (AT III, 505: Bos 2002, 115). Many of Descartes’ suggestions were incorporated, as amendments, into the final version of the Regius’ reply to Voetius, which appeared as Responsio, sive notae in Appendicem (Regius 1642) on 16 February 1642. This further inflamed the situation. The following month, Regius was forbidden by the University to teach natural philosophy in public or in private, and was restricted to lecturing in traditional medicine. The Academic Senate, with the approval of the town council, also issued an official condemnation of Cartesian philosophy. 