Yet even this method of describing Justice is not satisfactory to Plato, who was not content unless he started from the universal concepts of the Ideal world. The second portion of the dialogue describes how knowledge is gained. The mind discards the sensible and material world, advancing to the Ideas themselves. Yet even these are insufficient, for they all are interconnected and united to one great and architectonic Idea, that of the Good; to this the soul must advance before its knowledge can be called perfect. This is the scheme of education for the Guardians; the philosophic contemplation of Ideas, however, should be deferred till they are of mature age, for philosophy is dangerous in young men. Having performed their warlike functions of defending the State, the Guardians are to be sifted, those most capable of philosophic speculation being employed as instructors of the others. Seen from the height of the Ideal world, Justice again turns out to be the performance of one's own particular duties. This ideal society Plato admits to be a difficult aim for our weak human nature; he stoutly maintains, however, that "a pattern of it is laid up in heaven", man's true home. He mournfully grants that a declension from excellence is often possible and describes how this rule of philosophers, if established, would be expected to pass through oligarchy to democracy, the worst form of all government, peopled by the democratic man whose soul is at war with itself because it claims to do as it likes. The whole dialogue ends in an admirable vision in which he teaches that man chose his lot on earth in a preexisting state. Such is a fragmentary description of this masterpiece. What is it all about? First it is necessary to point out a serious misconception. Plato is not here advocating universal communism; his state postulates a money-making class and a labouring class also. Apart from the fact that he explicitly mentions these and allows them private property, it would be difficult to imagine that they are not rendered necessary by his very description of Justice. Not all men are fit for government--and therefore those who are governed must "do their particular business" for which they are fitted; in some cases it is the rather mean business of piling up fortunes. Communism is advocated as the only means of creating first and then propagating the small Guardian caste. Nor again is the caste rigid, for some of the children born of communistic intercourse will be unfit for their position and will be degraded into the money-making or property owning section. Communism to Plato is a high creed, too high for everybody, fit only for the select and enlightened or teachable few.