Note 84 — Chapter XXVIII · THEÆTETUS.

Thus in the Philêbus (pp. 55-56) Plato declares that numbering, measuring, and weighing, are the characteristic marks of all the various processes which deserve the name of Arts; and that among the different Arts those of the carpenter, builder, &c., are superior to those of the physician, pilot, husbandman, military commander, musical composer, &c., because the two first-named employ more measurement and a greater number of measuring instruments, the rule, line, plummet, compass, &c.

“When we talk about iron or silver” (says Sokrates in the Platonic Phædrus, p. 263 A-B) “we are all of one mind, but when we talk about the Just and the Good we are all at variance with each other, and each man is at variance with himself”. Compare an analogous passage, Alkibiad. I. p. 109.

Here Plato himself recognises the verifications of sense as the main guarantee for accuracy: and the compared facts of sense, when select and simplified, as ensuring the nearest approach to unanimity among believers.