  It might be thought that since Aristotle's theory treats mental functions and other vital functions exactly alike, it obscures a crucial distinction. This worry, however, turns out to be unjustified. The theory treats mental and other vital functions alike only in that it views both kinds of functions as performed by natural organisms of the right kind of structure and complexity. Viewing mental and other vital functions in this way is perfectly compatible with introducing a distinction between mental and other functions if concerns of some kind or other call for such a distinction.  Aristotle is perfectly capable, for instance, of setting aside non-mental vital functions as irrelevant for the purposes of practical philosophy  (NE 1.13, 1102b11-12).