There have been philosophers who separated these two parts; they called intelligence or discursive reason the understanding which is exercised without imagination and sensation; and opinion, the understanding which is exercised with imagination and sensation. Others, on the contrary, considered rational "being," or nature, a simple essence, and attributed to it operations whose nature is entirely different. Now it is unreasonable to refer to the same essence faculties which differ completely in nature; for thought and sensation could not depend on the same essential principle; and if we were to call the operation of intelligence a perception, we would only be juggling with words. We must, therefore, establish a perfectly clear distinction between these two entities, intelligence and sensibility. On the one hand, intelligence possesses a quite peculiar nature, as is also the case with discursive reason, which is next below it. The function of the former is intuitive thought, while that of the latter is discursive thought. On the other hand, sensibility differs entirely from intelligence, acting with or without the help of organs; in the former case, it is called sensation; in the latter, imagination. Nevertheless, sensation and imagination belong to the same genus. In understanding, intuitive intelligence is superior to opinion, which applies to sensation or imagination; this latter kind of thought, whether called discursive thought, or anything else (such as opinion), is superior to sensation and imagination, but inferior to intuitive thought. OF ASSENT. Numenius, who teaches that the faculty of assent (or, combining faculty) is capable of producing various operations, says that representation (fancy) is an accessory of this faculty, that it does not, however, constitute either an operation or function of it, but a consequence of it. The Stoics, on the contrary, not only make sensation consist in representation, but even reduce representation to (combining) assent. According to them sense-imagination (or sense-fancy) is assent, or the sensation of the determination of assent. Longinus, however, does not acknowledge any faculty of assent. The philosophers of the ancient Academy (the Platonists) believe that sensation does not comprise sense-representation, and that, consequently, it does not have any original property, since it does not participate in assent. If sense representation consisted of assent added to sensation, sensation, by itself, will have no virtue, since it is not the assent given to the things we possess. OF THE PARTS OF THE SOUL. It is not only about the faculties that the ancient philosophers disagree.... They are besides in radical disagreement about the following questions: What are the parts of the soul; what is a part; what is a faculty; what difference is there between a part and a faculty?