Institutio Oratoria

This form of proof may be countered in three ways, that is to say it may be attacked in all its parts. For either the major premise or the minor or the conclusion or occasionally all three are refuted. The major premise is refuted in the following case:

I was justified in killing him, as he lay in wait for me.

For the very first question in the defence of Milo is

whether it is right that he who confesses that he has killed a man should look upon the light of day.