Book, Paragraph

 1      I, 1 |          needs either one or more propositions, which are indeed the necessary
 2      I, 3 |        like the other affirmative propositions.~
 3      I, 13|           And similarly the other propositions in this mode can be converted.
 4      I, 14|         the manner of problematic propositions, the same syllogism results
 5      I, 15|           belongs to all C. These propositions being laid down, it is necessary
 6      I, 17|       convertible. Further, these propositions are not incompatible, "A
 7      I, 17|           convertibility of these propositions by a reductio ad absurdum,
 8      I, 17|     belong to all. Hence both the propositions "A necessarily belongs to
 9      I, 19|         same way as for universal propositions, and by the same terms.
10      I, 20|         in the case of assertoric propositions. Suppose that A may possibly
11      I, 25| established by different pairs of propositions; e.g. the conclusion E may
12      I, 25|           established through the propositions A and B, and through the
13      I, 25|          A and B, and through the propositions C and D, or through the
14      I, 25|           C and D, or through the propositions A and B, or A and C, or
15      I, 25|         Or again when each of the propositions A and B is obtained by syllogistic
16      I, 25|            or one or other of the propositions A and B, or something other
17      I, 25|          to make a syllogism, the propositions will have been assumed to
18      I, 25|         sort.~(2) But if from the propositions A and B there follows not
19      I, 25|           it turns out that these propositions have been assumed to no
20      I, 27|         normal antecedents -, for propositions which obtain normally are
21      I, 29|          Similarly with the other propositions requiring proof. The proof
22      I, 32|          them is destroyed: these propositions being laid down, it is necessary
23      I, 32|       drawn by syllogism from the propositions assumed, but premisses are
24      I, 32|    something results when certain propositions are assumed, we must not
25     II, 1 |         refuting and establishing propositions, and how we should investigate
26     II, 1 |        stated conclusion. For all propositions are convertible save only
27     II, 5 |      circular: for neither of the propositions assumed is the same as before:
28     II, 5 |    Consequently each of the three propositions has been made a conclusion,
29     II, 5 |         premiss through the other propositions, but the particular premiss
30     II, 5 |       universal is proved through propositions which are universal, but
31     II, 16|       reciprocal proof with three propositions.~Similarly if he should
32     II, 18|        and G, one of these higher propositions must be false, and on this
33     II, 19|     instead of inviting assent to propositions which are closely connected
34     II, 20|        are related in affirmative propositions or one proposition is affirmative,
35     II, 21|       unless he considers the two propositions together. So it is evident