  Aristotle approaches his account of the nutritive soul by relying on a methodological precept which informs much of his psychological theorizing, namely that a capacity is individuated by its objects, so that, e.g., perception is distinguished from mind by being arrayed toward sensible qualities rather than intelligible forms (De Anima ii 4, 415a20–21). This induces him to offer what may sound initially like a pedestrian observation, that in nutrition there are three components, “that which is nourished, that by which it is nourished, and what nourishes (i.e. that which engages in nutrition).” This, however, Aristotle unpacks by maintaining that “what nourishes is the primary soul; what is nourished is the body which has this soul; and that by which it is nourished is nourishment (i.e. food)” (De Anima ii 4, 416b20–23). The interest of this suggestion lies in the implication that all and only living systems can be nourished, a consequence Aristotle makes more explicit by claiming that “nothing is nourished which does not have a share in life” (De Anima ii 4. 415b27–28) and that “since nothing is nourished which does not partake of life, what is nourished will be the ensouled body insofar as it is ensouled, with the result that nourishment (i.e. food) is related to the ensouled, and not coincidentally” (De Anima ii 4, 416b9–11). Here Aristotle means that food, as food, is definitionally related to life. Whatever is food is already such as to be necessarily related to living beings.