Decree Fidei catholicae fundamento (1311-1312), Denzinger no. 481

Furthermore, every doctrine or proposition rashly asserting, or calling into doubt, that the substance of the rational or intellective soul is not truly and of itself the form of the human body, we reprove, with the approval of the aforesaid sacred Council, as erroneous and hostile to the catholic truth of the faith; defining, so that the truth of sincere faith may be known to all and the way to all errors closed lest they creep in, that whoever shall henceforth presume to assert, defend or obstinately hold that the rational or intellective soul is not of itself and essentially the form of the human body, is to be reckoned a heretic.