Book 5
10.16
With regard to credibility there are three degrees. First, the highest, based on what usually happens, as for instance the assumption that children are loved by their parents. Secondly, there is the highly probable, as for instance the assumption that a man in the enjoyment of good health will probably live till to-morrow. The third degree is found where there is nothing absolutely against an assumption, such as that a theft committed in a house was the work of one of the household.
10.17
Consequently Aristotle in the second book of his Rhetoric has made a careful examination of all that commonly happens to things and persons, and what things and persons are naturally adverse or friendly to other things or persons, as for instance, what is the natural result of wealth or ambition or superstition, what meets with the approval of good men, what is the object of a soldier's or a farmer's desires, and by what means everything is sought or shunned.
10.18
For my part I do not propose to pursue this subject. It is not merely a long, but an impossible or rather an infinite task; moreover it is within the compass of the common understanding of mankind. If, however, anyone wishes to pursue the subject, I have indicated where he may apply.
