The reasons which have inclined me to agree with Dr. Donaldson and also with Schleiermacher in supposing that 216 is the Platonic number of births are: (1) that it coincides with the description of the number given in the first part of the passage ([Greek: e)n ô(=| prô/tô| ... {cxxxiv} a)pe/phêsan]): (2) that the number 216 with its permutations would have been familiar to a Greek mathematician, though unfamiliar to us: (3) that 216 is the cube of 6, and also the sum of 3^3, 4^3, 5^3, the numbers 3, 4, 5 representing the Pythagorean triangle, of which the sides when squared equal the square of the hypotenuse (3^2 + 4^2 = 5^2): (4) that it is also the period of the Pythagorean Metempsychosis: (5) the three ultimate terms or bases (3, 4, 5) of which 216 is composed answer to the third, fourth, fifth in the musical scale: (6) that the number 216 is the product of the cubes of 2 and 3, which are the two last terms in the Platonic Tetractys: (7) that the Pythagorean triangle is said by Plutarch (de Is. et Osir., 373 E), Proclus (super prima Eucl. iv. p. 111), and Quintilian (de Musica iii. p. 152) to be contained in this passage, so that the tradition of the school seems to point in the same direction: (8) that the Pythagorean triangle is called also the figure of marriage ([Greek: gamê/lion dia/gramma]). But though agreeing with Dr. Donaldson thus far, I see no reason for supposing, as he does, that the first or perfect number is the world, the human or imperfect number the state; nor has he given any proof that the second harmony is a cube. Nor do I think that [Greek: a)r)r(ê/tôn de\ duei=n] can mean 'two incommensurables,' which he arbitrarily assumes to be 2 and 3, but rather, as the preceding clause implies, [Greek: duei=n a)rithmoi=n a)po\ a)r)r(ê/tôn diame/trôn pempa/dos], i.e. two square numbers based upon irrational diameters of a figure the side of which is 5 = 50 x 2. The greatest objection to the translation is the sense given to the words [Greek: e)pi/tritos puthmê/n k.t.l.], 'a base of three with a third added to it, multiplied by 5.' In this somewhat forced manner Plato introduces once more the numbers of the Pythagorean triangle. But the coincidences in the numbers which follow are in favour of the explanation. The first harmony of 400, as has been already remarked, probably represents the rulers; the second and oblong harmony of 7600, the people.