Institutio Oratoria

Some have recognised only two bases. Archedemus [*](Fr. 11, Arnim.) for instance admits only the conjectural and definitive and refuses to admit the qualitative, since he held that questions of quality take the form of

What is unfair? what is unjust? what is disobedience?

A different view was held by those who likewise only admitted two bases, but made them the negative and juridical. The negative basis is identical with that which we call the conjectural, to which some give the name of negative absolutely, others only in part, these latter holding that conjecture is employed by the accuser, denial only by the accused.

The juridical is that known in Greek as δικαιολογικός But just as Archedemus would not recognise the qualitative basis, so these reject the definitive which they include in the juridical, holding

Pamplihlus held this opinion but subdivided quality into several different species. The majority of later writers have classified bases as follows, involving however no more than a change of names:— those dealing with ascertained facts and those dealing with matters where there is a doubt. For a thing must either be certain or uncertain: if it is uncertain, the basis will be conjectural; if certain, it will be some one of the other bases.

Apollodorus says the same thing when he states that a question must either lie in things external, [*](e.g. circumstantial evidence. ) which give play to conjecture, or in our own opinions: the former he calls πραγματικός the latter περὶ ἐννοίας The same is said by those who employ the terms ἀπροληπτὸς [*](ἀπροληπτός lit. = unpresumed. ) and προληπτικός, that is to say doubtful and presumptive, by this latter term meaning those facts which are beyond a doubt.