Aristotle's accounts of the so-called 'practical syllogism', similarly, ascribe to the desires a sorting or discriminatory power: our of the man things presented to the agent by thought and perception, desire will single out some and not others to be foundations of action. Sometimes this selecting role is played by rational desire or 'wish'; but the appetitive forms of desire, too, 'speak', informing the whole creature of its needs and responding directly to the presence of what will satisfy those needs.... None of the appetites, not even the appetite for food, which Plato seems to hold throughout his life in unmitigated contempt, lacks, properly trained, its cognitive function. A well-formed character is a unity of thought and desire, in which choice has so blended these two elements, desire being attentive to thought and thought responsive to desire, that either one can guide and their guidance will be one and the same.
[Martha Nussbaum, The Fragility of Goodness: Luck and Ethics in Greek Tragedy and Philosophy, Updated Edition, Cambridge University Press (New York: 2009) p. 308.]
