For there to be Self-Consciousness, Desire must therefore be directed toward a non-natural object, toward something that goes beyond the given reality. Now, the only thing that goes beyond the given reality is Desire itself. For Desire taken as Desire – i.e., before its satisfaction – is but a revealed nothingness, an unreal emptiness. Desire, being the revelation of an emptiness, the presence of the absence of a reality, is something essentially different from the desired thing, something other than a thing, than a static and given real being that stays eternally identical to itself. Therefore, Desire directed toward another Desire, taken as Desire, will create, by the negating and assimilating action that satisfies it, an I essentially different from the animal "I".

Friedrich Hegel, "Autonomy and Dependence of Selfconsciousness: Mastery and Slavery" in Introduction to the Reading of Hegel (Cornell University Press, 1980) p. 5

In contrast to the knowledge that keeps man in a passive quietude, Desire dis-quiets him and moves him to action. Born of Desire, action tends to satisfy it, and can do so only by the "negation," the destruction, or at least the transformation, of the desired object: to satisfy hunger, for example, the food must be destroyed or, in any case, transformed. Thus, all action is "negating." Far from leaving the given as it is, action destroys it; if not in its being, at least in its given form. And all "negating-negativity" with respect to the given is necessarily active. But negating action is not purely destructive, for if action destroys an objective reality, for the sake of satisfying the Desire from which it is born, it creates in its place, in and by that very destruction, a subjective reality. The being that eats, for example, creates and preserves its own reality by the overcoming of a reality other than its own, by the "transformation" of an alien reality into its own reality, by the "assimilation," the "internalization" of a "foreign," "external" reality. Generally speaking, the I of Desire is an emptiness that receives a real positive content only by negating action that satisfies Desire in destroying, transforming, and "assimilating" the desired non-I.

Friedrich Hegel, "Autonomy and Dependence of Selfconsciousness: Mastery and Slavery" in Introduction to the Reading of Hegel (Cornell University Press, 1980) p. 4