spinoza on the body

For what the body can do no one has hitherto determined,
that is to say experience has taught no one hitherto what the body without being determined by the mind, can do, and what it cannot do form the laws of nature alone, in so far as the nature is considered merely as corporeal. For no one as yet has understood the struture of the body so accurately as to be able to explain all its functions,
not to mention the fact that many brutes which far surpass human sagacity and that sleep walkers in their sleep do very many things which they dare not do when awake. (Ethics 3rd part 101)