XXXVII.  And from these considerations that also is evident, that there is a certain kind of argumentation in which neither proposition nor assumption stands in need of proof, of this sort, that we may adduce something undoubted and concise, for the sake of example.  “If wisdom is above all things to be desired, then folly is above all things to be avoided; but wisdom is to be desired above all things, therefore folly is above all things to be avoided.”  Here both the assumption and the proposition are self-evident, on which account neither of them stands in need of proof.  And from all these facts it is manifest that proof is at times added, and at times is not added.  From which it is palpable that proof is not contained in a proposition, nor in an assumption, but that each being placed in its proper place, has its own peculiar force fixed and belonging to itself.  And if that is the case, then those men have made a convenient arrangement who have divided argumentation into five parts.

Are there five parts of that argumentation which is carried on by ratiocination?  First of all, proposition, by which that topic is briefly explained from which all the force of the ratiocination ought to proceed.  Then the proof of the proposition, by which that which has been briefly set forth being corroborated by reasons, is made more probable and evident.  Then assumption, by which that is assumed which, proceeding from the proposition, has its effect on proving the case.  Then the proof of the assumption, by which that which has been assumed is confirmed by reasons.  Lastly, the summing up, in which that which results from the entire argumentation is briefly explained.  So the argumentation which has the greatest number of divisions consists of these five parts.

The second sort of argumentation has four divisions; the third has three.  Then there is one which has two; which, however, is a disputed point.  And about each separate division it is possible that some people may think that there is room for a discussion.

XXXVIII.  Let us then bring forward some examples of those matters which are agreed upon.  And in favour of those which are doubtful, let us bring forward some reasons.  Now the argumentation which is divided into five divisions is of this sort:—­It is desirable, O judges, to refer all laws to the advantage of the republic, and to interpret them with reference to the general advantage, and according to the strict wording according to which they are drawn up.  For our ancestors were men of such virtue and such wisdom, that when they were drawing up laws, they proposed to themselves no other object than the safety and advantage of the republic; for they were neither willing themselves to draw up any law which could be injurious; and if they had drawn up one of such a character, they were sure that it would be rejected when its tendency was perceived.  For no one wishes to preserve the laws for the sake of the laws, but