son; but to the philosopher, and to him who investigates by himself, it is no concern, if the particulars through which the syllogism is constructed, be true and known, whether the respondent admits them or not, because of their nearness to the original question, and from their foreseeing the result; they even perhaps would endeavour that axioms should be especially known and approximate, as from these, scientific syllogisms subsist.
The places then, whence we must derive (arguments), have been enunciated before, but we must speak of order, and interrogation, distinguishing the propositions which are to be assumed, besides such as are necessary. Now those are called necessary, through which a syllogism arises, but those assumed besides these, are four; for (they are so), either for the sake of induction that the universal may be granted; or for amplifying what is said; or for concealment of the conclusion; or for greater perspicuity of expression. Besides these however, we must assume no proposition, but endeavour through these to increase, and to interrogate: those which are for concealment (are to be assumed) for the sake of contention, yet since the whole of this treatise is with reference to another person, it is necessary to use these also.
The necessary (propositions) then through which a syllogism arises, must not be advanced immediately, but we must retire to what is highest; for instance, not requiring it to be granted, that there is the same science of contraries, if it is desired to assume this, but of opposites, for when this is laid down, it will be syllogistically inferred that there is the same of contraries also, since contraries are opposites. If, again, (a person) does
