Institutio Oratoria

Aristotle [*]( Ar. Rhet. 1416 b : 1374 a . ) in his Rhetoric states that all enquiry turns on the questions whether a thing is, of what kind it is, how great it is, and of how many parts it consists. In one place however he recognises the force of definition as well, saying that certain points are defended on the following lines:—

I took it, but did not steal it.

I struck him, but did not commit an assault.

Cicero [*](de Inv. I. viii. 10. ) again in his Rhetorica makes the number of bases to be four, namely those concerned with fact, names, kinds, and legal action, that is to say conjecture is concerned with fact, definition with names, quality with kinds, and law with action: under this latter head of law he included questions of competence. But in another passage he treats [*](Part. Or. 31 and 38. ) legal questions as a species of action. Some writers have held that there are five bases: