That reason is not instructed by the body, that even the part of the body to which the soul is immediately joined is neither perceptible nor intelligible by itself, that neither our body nor those surrounding it can be our mind's immediate object, that we cannot learn from our brain whether it actually exists, much less whether there are bodies surrounding us; that we must therefore recognize that there is some superior intelligence that alone is capable of acting on us, and that can act on us in such a way as to truly represent to us bodies outside us, without giving us the least idea of our brain, though the motion produced in our brain is an occasion for this intelligence to reveal these bodies to us.