Explain Aristotle's critique on Plato's idealism.

Aristotle is the greatest disciple as well as the greatest critique of Plato. Plato advocates idealism in his theories and Aristotle is a rational thinker which make him the critique of Plato. Both have different perspectives about the existence of idea, one believes reality is mere a reflection of idea and other believes idea is inside the reality, if reality goes away its also goes away. For Plato reality and idea are two different worlds but for Aristotle reality and idea exist together.

Aristotle criticize Plato's idea of justice. Plato in his state only give duty and no rights. He put power in one hand, absolute power can degrade the system. There is no all round development of individual only functional specialization based on his theory of myths of metal and there is no judicial system.

Aristotle is the biggest critique of Plato's theory of philosopher king(PK). For Aristotle, PK is the best form of government but not practicable. PK is a just man who have a just soul. According to Plato, only just man can make a just state. A state of bliss and prosperity. Aristolte criticize Plato by calling it a utopia. His concern is soul of man contain both reason and appetite even if PK have 99% reason but he also have appetite and it may dominate one day. 

In order to create an ideal state/ just state, Plato gave his theory of communism of family and property. In which Plato take away private ownership from ruling classes. He believes it promote corruption because of the essence of self attached with it. Aristotle is a supporter of property. He argue that property is the source of inspiration and motivation. It bring donation. It is a symbol of success and reason because only a man of reason with his skill and efforts can make his property. It brings qualities like generosity, hospitality and liberality.