Abstract: It seems that Plato presents us with two different patterns of the soul.One is the ascent model that the Eros harmoniously ascends towards the Idea of the Beautiful,while the other is the conflict model between the rational part of the soul and the non-rational part of the desire and passion.There is no inherent paradox existing in the two different models,but the two models could be seen as two different ways of describing the same practical theme:the order or the logic of desire.Plato did not develop a systematic practical philosophy in the two mentioned dialogues,but the two dialogues serve as an irreplaceable metaphysical foundation for the practical philosophy:moral psychology,namely,the tripartite structure of the soul and the nature of Eros.The government of the reason is the best constitution for the individual soul,and the final goal of Eros is the contemplation of the Idea of the Beautiful.Only in the contemplation of the Idea of the Beautiful and the Good can we find our ultimate realization,while the rational part of the soul become free of the enslavement of passions and desires,finally obtaining individuals' sense of justice through the cultivation of philosophy and the love of intelligence.

Key words: soul, reason, the beautiful, eros, Republic, Symposium