The passage is often read together with "Metaphysics", Book XII, ch.7-10, where Aristotle makes "nous" as an actuality a central subject within a discussion of the cause of being and the cosmos. In that book, Aristotle equates active "nous", when people think and their "nous" becomes what they think about, with the "unmoved mover" of the universe, and God: "For the actuality of thought ("nous") is life, and God is that actuality; and the essential actuality of God is life most good and eternal." Alexander of Aphrodisias, for example, equated this active intellect which is God with the one explained in "De Anima", while Themistius thought they could not be simply equated. (See below.)