Institutio Oratoria

Nor does it matter whether one recognises only one kind of basis or none at all, if all causes are of the same nature. Coniectura is derived from conicere

to throw together,

conjecturers.

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.

Theodorus agrees with them, for he holds that the question is either as to whether such and such a thing is really so, or is concerned with the accidents of something which is an admitted fact: that is to say it is either περὶ οὐσίας or περὶ συμβεβηκότων For in all these cases the first basis is conjectural, while the second belongs to one of the other classes. As for these other classes of basis, Apollodorus holds that there are two, one concerned with quality and the other with the names of things, that is to say a definitive basis. Theodorus makes them four, concerned with existence, quality, quantity and relation.

There are some too who make questions of identity and difference come under the head of quality, others who place it under the head

Even Cornelius Celsus stated that there were two general bases, one concerned with the question whether a thing is, the other with the question of what kind it is. He included definition under the first of these, because enquiry may equally be made as to whether sacrilege has been committed, when a man denies that he has stolen anything from a temple, and when he admits that he has stolen private money from a temple. He divides quality into fact and the letter of the law. Under the head of the letter of the law he places four classes, excluding questions of competence: [*](cp. § 23; translatio and exceptio are virtually identical. The four classes are Intention, Ambiguity, Contradictory Laws, Syllogism. ) quantity and intention he places under the head of conjecture. [*](i.e. the conjectural basis concerned with questions of fact. )