In the first and second books, I showed (a) that our senses and imqination are very useful to us in knowing the relations external bodies have to our own; (b) that all the ideas the mind receives through the body are entirely for the benefit of the body; (c) that no truth whatever can be clearly discovered through the idea of the senses or the imagination; (d) that these ideas serve only bind us our body and through it to all sensible things; and fmally; (e)