Prior Analytics - Book II   

to some C, and B to some C, e.g. animal belongs to no snow, but to

some white thing, and snow to some white thing. If then snow is

taken as middle, and animal as first term, and it is assumed that A

belongs to the whole of B, and B to some C, then the premiss BC is

wholly false, the premiss BC true, and the conclusion true.

Similarly if the premiss AB is negative: for it is possible that A

should belong to the whole of B, but not to some C, although B belongs

to some C, e.g. animal belongs to every man, but does not follow

some white, but man belongs to some white; consequently if man be

taken as middle term and it is assumed that A belongs to no B but B

belongs to some C, the conclusion will be true although the premiss AB

is wholly false. (If the premiss AB is false in part, the conclusion

may be true. For nothing prevents A belonging both to B and to some C,

and B belonging to some C, e.g. animal to something beautiful and to

something great, and beautiful belonging to something great. If then A

is assumed to belong to all B, and B to some C, the a premiss AB

will be partially false, the premiss BC will be true, and the

conclusion true. Similarly if the premiss AB is negative. For the same

terms will serve, and in the same positions, to prove the point.

(9) Again if the premiss AB is true, and the premiss BC is false,

the conclusion may be true. For nothing prevents A belonging to the

whole of B and to some C, while B belongs to no C, e.g. animal to

every swan and to some black things, though swan belongs to no black

thing. Consequently if it should be assumed that A belongs to all B,

and B to some C, the conclusion will be true, although the statement

BC is false. Similarly if the premiss AB is negative. For it is

possible that A should belong to no B, and not to some C, while B

belongs to no C, e.g. a genus to the species of another genus and to

the accident of its own species: for animal belongs to no number and

not to some white things, and number belongs to nothing white. If then

number is taken as middle, and it is assumed that A belongs to no B,

and B to some C, then A will not belong to some C, which ex