Imagination arises in the same way as perception, except that it is not caused by external objects. Continuing the just-quoted passage, Descartes wrote: “And note that I say ‘imagines or perceives by the senses’. For I wish to apply the term ‘idea’ generally to all the impressions which the spirits can receive as they leave gland H. These are to be attributed to the ‘common’ sense when they depend on the presence of objects; but they may also proceed from many other causes (as I shall explain later), and they should then be attributed to the imagination” (AT XI:177, CSM I:106). Descartes’ materialistic interpretation of the term ‘idea’ in this context is striking. But this is not the only sense in which he used this term: when he was talking about real men instead of mechanical models of their bodies, he also referred to ‘ideas of the pure mind’ which do not involve the ‘corporeal imagination’.