Book 5
14.5
As regards the epicheieme, some authorities hold that it consists of four, five, and even six parts. Cicero de Inv. I. xxxvii. 67. urges that there are not more than five at most, i.e. the major premise and its reason, the minor premise and its proof, and fifthly the conclusion. But since at times the major premise does not require a reason nor the minor a proof, while occasionally even the conclusion is not necessary, he holds that the epicheireme may consist of only four, three, or even two parts.
14.6
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.
