  These early hints, which were short of an outright denial of a pure understanding, were interpreted correctly by Descartes in 1647. Regius had defined perception in his banned disputation as ‘sensation, remembering and imagining’ (Regius 1647b: Corollaries, no. 18), and Descartes concluded that he was implicitly denying the reality of pure understanding: “One could draw the conclusion that he does not accept any pure understanding, that is, an understanding that is not concerned with physical images; and therefore he thinks that we have no knowledge of God or the human soul, or of other non-physical things” (AT VIII-2, 363). Regius confirmed that interpretation in his reply: “The human mind, although it is a substance that is really distinct from the body, is however organic in all its actions while it is in the body … it cannot perform any of its actions without bodily organs” (Regius 1648, 10).  Perhaps he had been applying Descartes’ previous advice about substantial forms—to ignore them rather than deny their existence explicitly—when he refrained from denying a pure understanding in his earlier writings. By 1654, however, he was ready to publish an explicit denial: “Since … we are able to explain all its operations [i.e., those of the mind] by those faculties of the intellect, which were already explained, there is no need to add to them a pure intellect or anything similar as something that is distinct from them” (Regius 1654, 404). Nonetheless, the denial of a pure intellect did not imply denying that human beings have an idea of God; the latter is acquired in the same way as other ideas, namely by using an intellect that is organically dependent on the human body.