In philosophy, desire has been identified as a recurring philosophical problem. It has been variously interpreted as what compels someone towards the highest state of human nature or consciousness, as well as being posited as either something to be eliminated or a powerful source of potential. In Plato's The Republic, Socrates argued that individual desires must be postponed in the name of a higher ideal. Similarly, within the teachings of Buddhism, craving, identified as the most potent form of desire, is thought to be the cause of all suffering, which can be eliminated to attain greater happiness (Nirvana). While on the path to liberation, a practitioner is advised to "generate desire" for skillful ends. History Ancient Greece In Aristotle's De Anima the soul is seen to be involved in motion, because animals desire things and in their desire, they acquire locomotion. Aristotle argued that desire is implicated in animal interactions and the propensity of animals to motion. But Aristotle acknowledges that desire cannot account for all purposive movement towards a goal. He brackets the problem by positing that perhaps reason, in conjunction with desire and by way of the imagination, makes it possible for one to apprehend an object of desire, to see it as desirable. In this way reason and desire work together to determine what is a good object of desire. This resonates with desire in the chariots of Plato's Phaedrus, for in the Phaedrus the soul is guided by two horses, a dark horse of passion and a white horse of reason. Here passion and reason, as in Aristotle, are also together. Socrates does not suggest the dark horse be done away with, since its passions make possible a movement towards the objects of desire, but he qualifies desire and places it in a relation to reason so that the object of desire can be discerned correctly, so that we may have the right desire. Aristotle distinguishes desire into two aspects of appetition, and volition. Appetition, or appetite, is a longing for or seeking after something; a craving. Aristotle makes the distinction as follows: Everything, too, is pleasant for which we have the desire within us, since desire is the craving for pleasure. Of the desires some are irrational, some associated with reason. By irrational I mean those which do not arise from any opinion held by the mind. Of this kind are those known as ‘natural’;