certain C, but B with no C, as genus with species of another genus, and with an accident of its own species, for animal is with no number, but with something white, and number with nothing white. If then A is assumed present with every B, and B with a certain C, the conclusion indeed will be true while both the premises will be false.
Likewise if A B is negative, for nothing prevents A from being with the whole of B, and from not being with a certain C, and B from being with no C, thus animal is with every swan, but is not with something black, swan however is with nothing black. Wherefore, if A is assumed present with no B, but B with a certain C, A is not with a certain C, and the conclusion will be true, but the premises false.
Chapter 3
In the middle figure it is altogether possible to infer truth from false premises, whether both are assumed wholly false, or one partly, or one true, but the other wholly false, whichever of them is placed false, or whether both are partly false, or one is simply true, but the other partly false, or one is wholly false, but the other partly true, and as well in universal as in particular syllogisms. For if A is with no B but with every C, as animal is with no stone but with every horse, if the propositions are placed contrariwise, and A is assumed present with every B, but with no C, from premises wholly false, the conclusion will be true. Likewise if A is with every B but with no C, for the syllogism will be the same.
