On the Syllogisms Compounded of Separative Propositions

Abstract

We say: There is never a syllogism from two real separative premisses. For the statement ‘It is exclusively either A is B or C is D’ is true only if it has no third part. What is meant by saying ‘It is exclusively either A is B or C is D’ is the following: ‘A is B, and if not, then it is necessary that C is D’. If it is not the case that ‘C is D’, then the statement will be false. Except, as we said before ¹, when you turn it into a particular proposition; for in this case it should not take a third part. We shall prove that there is no syllogism from two affirmative premisses one of which is a particular premiss.