5.

In this whole forest of images, I believe that you do not think that those of the first class belong to the mind previous to the time when they find access through the senses. On this we need not argue any further. As to the other two classes a question might reasonably be raised, were it not manifest that the mind is less liable to illusions when it has not yet been subjected to the deceptive influence of the senses, and of things sensible; and yet who can doubt that these images are much more unreal than those with which the senses acquaint us? For the things which we suppose, or believe, or picture to ourselves, are in every point wholly unreal; and the things which we perceive by sight and the other senses, are, as you see, far more near to the truth than these products of imagination. As to the third class, whatever extension of body in space I figure to myself in my mind by means of an image of this class, although it seems as if a process of thought had produced this image by scientific reasonings which did not admit of error, nevertheless I prove it to be deceptive, these same reasonings serving in turn to detect its falsity. Thus it is wholly impossible for me to believe [as, accepting your opinion, I must believe] that the soul, while not yet using the bodily senses, and not yet rudely assaulted through these fallacious instruments by that which is mortal and fleeting, lay under such ignominious subjection to illusions.