Book 3
5.29
I find it stated in many authors that some rhetoricians only recognise one kind of basis, the con- jectural. But they have not mentioned who these rhetoricians are nor have I been able to discover. They are however stated to have taken this view on the ground that all our knowledge is a matter of inference from indications. On this line of reasoning they might regard all bases as qualitative, because we inquire into the nature of the subject in every case. But the adoption of either view leads to inextricable confusion.
5.30
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, because it implies the concentration of the reason on the truth. For this reason interpreters of dreams and all other phenomena are called coniectores conjecturers. But the conjectural basis has received more names than one, as will appear in the sequel.
5.31
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? which he terms questions about identity and difference. i.e. the question may be stated Does it conform to our conception of injustice or is it something different? Questions of quality are regarded as questions of definition.