The Greek psuchē is a broader concept than can be equated with either “mind” or “soul”: it is the vital principle—that the presence of which accounts for life in the body—as well as more specifically the locus of thought and moral activity. All vital activities, in this sense, can be defined as “of the psuchē”, which is thus responsible for both (in our terms) mental and physical function. The hēgemonikon is responsible for intellectual activity and memory, for voluntary motion and for perception; and each of these is also to be understood in terms of brain and/or nerve function. It is tempting, in view of the correlations that Galen explores, both between the functioning of the rational soul and states of the brain, and between emotional disturbances and states or activities of the heart and blood, to see him as advancing either some form of dual aspect theory or, indeed, a mind–body identity theory. It seems clear, however, that Galen does not in any clear or consistent way elaborate such a clear or unified scheme (see further §7.2).