The preliminary sciences must be imparted to our Guardians during the earlier years of life, together with such bodily and mental training as may test their energy and perseverance of character.[249] After the age of twenty, those who have distinguished themselves in the juvenile studies and gymnastics, must be placed in a select class of honour above the rest, and must be initiated in a synoptic view of the affinity pervading all the separate cognitions which have been imparted to them. They must also be introduced to the view of Real Essence and its nature. This is the test of aptitude for Dialectics: it is the synoptic view only, which constitutes the Dialectician.[250] [Footnote 249: Plato, Republic, vii. p. 535-536 D.] [Footnote 250: Plato, Republic, vii. pp. 536-537 C. [Greek: kai\ megi/stê pei=ra dialektikê=s phu/seôs kai\ mê/; o( me\n ga\r sunoptiko\s dialektiko/s, o( de\ mê/, ou)/.]] In these new studies they will continue until thirty years of age: after which a farther selection must be made, of those who have most distinguished themselves. The men selected will be enrolled in a class of yet higher honour, and will be tested by dialectic cross-examination: so that we may discover who among them are competent to apprehend true, pure, and real Essence, renouncing all visual and sensible perceptions.[251] It is important that such Dialectic exercises should be deferred until this advanced age--and not imparted, as they are among us at present, to immature youths: who abuse the license of interrogation, find all their homegrown opinions uncertain, and end by losing all positive convictions.[252] Our students will remain under such dialectic tuition for five years, until they are thirty-five years of age: after which they must be brought again down into the cave, and constrained to acquire practical experience by undertaking military and administrative functions. In such employments they will spend fifteen years: during which they will undergo still farther scrutiny, to ascertain whether they can act up to their previous training, in spite of all provocations and temptations.[253] Those who well sustain all these trials will become, at fifty years of age, the finished Elders or Chiefs of the Republic. They will pass their remaining years partly in philosophical contemplations, partly in application of philosophy to the regulation of the city. It is these Elders whose mental eye will have been so trained as to contemplate the Real Essence of Good, and to copy it as an archetype in all their ordinances and administration. They will be the Moderators of the city: but they will perform this function as a matter of duty and necessity--not being at all ambitious of it as a matter of honour.[254] [Footnote 251: Plato, Republic, p. 537 D.] [Footnote 252: Plato, Republic, vii. pp. 538-539.] [Footnote 253: Plato, Republic, vii. p. 539 D-E.] [Footnote 254: Plato, Republic, vii. pp. 539-540.]