Institutio Oratoria

Personally however follow the majority of authorities in holding that there are not more than three parts. For it follows from the very nature of reasoning that there must be something to form the subject of enquiry and something else to provide the proof, while the third element which has to be added may be regarded as resulting from the agreement of the two previous

elements. Thus the first part will be the major, the second the minor premise and the third the conclusion. For the confirmation and development of both premises may reasonably be included in the parts to which they belong.