Home | Texts by category | | Quick Search:   
Works by Aristotle
Pages of Prior Analytics - Book II

Previous | Next

Prior Analytics - Book II   

convertible with B, B is convertible also with A, for C is said of

that of all of which B is said. And if C is convertible in relation to

A and to B, B also is convertible in relation to A. For C belongs to

that to which B belongs: but C does not belong to that to which A

belongs. And this alone starts from the conclusion; the preceding

moods do not do so as in the affirmative syllogism. Again if A and B

are convertible, and similarly C and D, and if A or C must belong to

anything whatever, then B and D will be such that one or other belongs

to anything whatever. For since B belongs to that to which A

belongs, and D belongs to that to which C belongs, and since A or C

belongs to everything, but not together, it is clear that B or D

belongs to everything, but not together. For example if that which

is uncreated is incorruptible and that which is incorruptible is

uncreated, it is necessary that what is created should be

corruptible and what is corruptible should have been created. For

two syllogisms have been put together. Again if A or B belongs to

everything and if C or D belongs to everything, but they cannot belong

together, then when A and C are convertible B and D are convertible.

For if B does not belong to something to which D belongs, it is

clear that A belongs to it. But if A then C: for they are convertible.

Therefore C and D belong together. But this is impossible. When A

belongs to the whole of B and to C and is affirmed of nothing else,

and B also belongs to all C, it is necessary that A and B should be

convertible: for since A is said of B and C only, and B is affirmed

both of itself and of C, it is clear that B will be said of everything

of which A is said, except A itself. Again when A and B belong to

the whole of C, and C is convertible with B, it is necessary that A

should belong to all B: for since A belongs to all C, and C to B by

conversion, A will belong to all B.

When, of two opposites A and B, A is preferable to B, and

similarly D is preferable to C, then if A and C together are

preferable to B and D together, A must be preferable to D. For A is an

Previous | Next
Site Search