Thus, you have learnt, and you know, the universal truth, that every triangle has its three angles equal to two right angles; but you do not yet know that A B C, D E F, G H I, &c., have their two angles equal to two right angles; for you have not yet seen any of these figures, and you do not know that they _are_ triangles. The moment that you see A B C, or hear what figure it is, you learn at one and the same time two facts: first, that it is a triangle; next, by virtue of your previous cognition, that it possesses the above-mentioned property. You knew this _in a certain way_ or incompletely before, by having followed the demonstration of the universal truth, and by thus knowing that _every_ triangle had its three angles equal to two right angles; but you did not know it absolutely, being ignorant that A B C was a triangle.[11] [Footnote 11: Aristot. Analyt. Post. I. i. p. 71, a. 17-b. 8: [Greek: e)/sti de\ gnôri/zein ta\ me\n pro/teron gnôri/zonta, tô=n de\ kai\ a)/ma lamba/nonta tê\n gnô=sin, oi(=on o(/sa tugcha/nei o)/nta u(po\ to\ katho/lou, ô(=n e)/chei tê\n gnô=sin. o(/ti me\n ga\r pa=n tri/gônon e)/chei dusi\n o)rthai=s i)/sas, proê/|dei; o(/ti de\ to/de to\ e)n tô=| ê(mikukli/ô| tri/gôno/n e)stin, a(/ma e)pago/menos e)gnô/risen.--pri\n d' e)pachthê=nai ê)\ labei=n sullogismo/n, tro/pon me/n tina i)/sôs phate/on e)pi/stasthai, tro/pon d' a)/llon ou)/. o(\ ga\r mê\ ê)/|dei ei) e)/stin a(plô=s, tou=to pô=s ê)/|dei o(/ti du/o o)rtha\s e)/chei a(plô=s? a)lla\ dê=lon ô(s _ô(di\ me\n e)pi/statai, o(/ti katho/lou e)pi/statai, a(plô=s d' ou)k e)pi/statai_.--ou)de\n (oi)=mai) kôlu/ei, o(\ mantha/nei, e)/stin ô(s e)pi/stasthai, e)/sti d' ô(s a)gnoei=n; a)/topon ga\r ou)k ei) oi)=de/ pôs o(\ mantha/nei, a)ll' ei) ô(di/, oi(=on ê(=| mantha/nei kai\ ô(/s.] Compare also Anal. Post. I. xxiv. p. 86, a. 23, and Metaph. A. ii. p. 982, a. 8; Anal. Prior. II. xxi. p. 67, a. 5-b. 10.) Aristotle reports the solution given by others, but from which he himself dissented, of the Platonic puzzle. The respondent was asked, Do you know that every Dyad is even?--Yes. Some Dyad was then produced, which the respondent did not know to be a Dyad; accordingly he did not know it to be even. Now the critics alluded to by Aristotle said that the respondent made a wrong answer; instead of saying I know every Dyad is even, he ought to have said. Every Dyad _which I know to be a Dyad_ is even. Aristotle pronounces that this criticism is incorrect. The respondent knows the conclusion which had previously been demonstrated to him; and that conclusion was, Every triangle has its three angles equal to two right angles; it was not, Every thing _which I know_ to be a triangle has its three angles equal to two right angles. This last proposition had never been demonstrated, nor even stated: [Greek: ou)demi/a ga\r pro/tasis lamba/netai toiau/tê, o(/ti _o(\n su\ oi)=das_ a)rithmo/n, _ê)\ o(\ su\ oi)=das_ eu)thu/grammon, a)lla\ _kata\ panto/s_] (b. 3-5).