([Greek: g]) But Plato has an equal, or, in his own estimation, even greater paradox in reserve, which is summed up in the famous text, 'Until kings are philosophers or philosophers are kings, cities will never cease from ill.' And by philosophers he explains himself to mean those who are capable of apprehending ideas, especially the idea of good. To the attainment of this higher knowledge the second education is directed. Through a process of training which has already made them good citizens they are now to be made good legislators. We find with some surprise (not unlike the feeling which Aristotle in a well-known passage describes the hearers of Plato's lectures as experiencing, when they went to a discourse on the idea of good, expecting to be instructed in moral truths, and received instead of them arithmetical and mathematical formulae) that Plato does not propose for his future legislators any study of finance or law or military tactics, but only of abstract mathematics, as a preparation for the still more abstract conception of good. We ask, with Aristotle, What is the use of a man knowing the idea of {cxcv} good, if he does not know what is good for this individual, this state, this condition of society? We cannot understand how Plato's legislators or guardians are to be fitted for their work of statesmen by the study of the five mathematical sciences. We vainly search in Plato's own writings for any explanation of this seeming absurdity. The discovery of a great metaphysical conception seems to ravish the mind with a prophetic consciousness which takes away the power of estimating its value. No metaphysical enquirer has ever fairly criticised his own speculations; in his own judgment they have been above criticism; nor has he understood that what to him seemed to be absolute truth may reappear in the next generation as a form of logic or an instrument of thought. And posterity have also sometimes equally misapprehended the real value of his speculations. They appear to them to have contributed nothing to the stock of human knowledge. The _idea_ of good is apt to be regarded by the modern thinker as an unmeaning abstraction; but he forgets that this abstraction is waiting ready for use, and will hereafter be filled up by the divisions of knowledge. When mankind do not as yet know that the world is subject to law, the introduction of the mere conception of law or design or final cause, and the far-off anticipation of the harmony of knowledge, are great steps onward. Even the crude generalization of the unity of all things leads men to view the world with different eyes, and may easily affect their conception of human life and of politics, and also their own conduct and character (Tim. 90 A). We can imagine how a great mind like that of Pericles might derive elevation from his intercourse with Anaxagoras (Phaedr. 270 A). To be struggling towards a higher but unattainable