Here we see that propositions G and H do not stand to B and A in the same relations as C and D stand to B and A; but that they stand in that same relation to two perfectly different propositions, F and E. That is, if in place of _non **justus_, in propositions G and H, we substitute the privative term _injustus_ (thus turning G into _Est injustus non homo_, and turning H into _Non est injustus non homo_), the relation of G, when thus altered, to F, and the relation of H, when thus altered, to E, will be the same as it was before. Or, in other words, if G be true, F will certainly be true, but not _vice versâ_; and if E be true, H will certainly be true, but not _vice versâ_. [Footnote 25: Aristot. De Interpr. p. 19, b. 36. [Greek: au(=tai me\n ou)=n du/o a)nti/keintai] (the two pairs--A B and C D--of the first quaternion), [Greek: a)/llai de\ du/o pro\s to\ _ou)k a)/nthrôpos_ ô(s u(pokei/meno/n ti prostethe/n;] (E) [Greek: e)/sti di/kaios ou)k a)/nthrôpos] ... ... ... (F) [Greek: ou)k e)/sti di/kaios ou)k a)/nthrôpos.] (H) [Greek: ou)k e)/stin ou) di/kaios ou)k a)/nthrôpos] ... (G) [Greek: e)/stin ou) di/kaios ou)k a)/nthrôpos.] [Greek: plei/ous de\ tou/tôn ou)k e)/sontai a)ntithe/seis. au(=tai de\ chôri\s e)kei/nôn au)tai\ kath' e(auta\s e)/sontai, ô(s o)no/mati tô=| _ou)k a)/nthrôpos_ chrô/menai.] The second [Greek: au(=tai] alludes to this last quaternion, [Greek: e)kei/nôn] to the first. I have, as in the former case, transposed propositions three and four of this second quaternion, in order that the relation of G to F and of H to E may be more easily discerned. There are few chapters in Aristotle more obscure and puzzling than the tenth chapter of the De Interpretatione. It was found so by Alexander, Herminus, Porphyry, Ammonius, and all the Scholiasts. Ammonius (Schol. pp. 121, 122, Br.) reports these doubts, and complains of it as a riddle almost insolvable. The difficulties remain, even after the long note of Waitz, and the literal translation of M. Barthélemy St. Hilaire.] The propositions which we have hitherto studied have been indefinite; that is, they might be universal or not. But if we attach to them the sign of universality, and construe them as universals, all that we have said about them would still continue to be true, except that the propositions which are diametrically (or diagonally) opposed would not be both true in so many instances. Thus, let us take the first quaternion of propositions, in which _est_ is attached to _homo_, and let us construe these propositions as universal. They will stand thus-- (A) Omnis est homo justus ... ... (B) Non omnis est homo justus. (D) Non omnis est homo non justus (C) Omnis est homo non justus.