Aristotle - The Organon - index for TOPICA Book 2 Part 8

Look for arguments among contradictories

Paragraph 1 Seeing that the modes of opposition are four in number, you should look for arguments among the contradictories of your terms, converting the order of their sequence, both when demolishing and when establishing a view, and you should secure them by means of induction - such arguments (e.g.) as that man be an animal, what is not an animal is not a man:
Paragraph 2 Then look also at the case of the contraries of S and P in the thesis, and see if the contrary of the one follows upon the contrary of the other, either directly or conversely, both when you are demolishing and when you are establishing a view:
Paragraph 3 You should look also into cases of the privation or presence of a state in like manner to the case of contraries.
Paragraph 4 The case of relative terms should also be studied in like manner to that of a state and its privation:

UPHOME HTML by RBJ created 1996/11/25 modified 2009/04/26