Book 7
1.45
An argument is in itself a whole containing premisses and conclusion, and an inference (or syllogism) is an inferential argument composed of these. Demonstration is an argument inferring by means of what is better apprehended something less clearly apprehended.
1.45
A presentation (or mental impression) is an imprint on the soul: the name having been appropriately borrowed from the imprint made by the seal upon the wax.
1.46
There are two species of presentation, the one apprehending a real object, the other not. The former, which they take to be the test of reality, is defined as that which proceeds from a real object, agrees with that object itself, and has been imprinted seal-fashion and stamped upon the mind: the latter, or non-apprehending, that which does not proceed from any real object, or, if it does, fails to agree with the reality itself, not being clear or distinct.
1.46
Dialectic, they said, is indispensable and is itself a virtue, embracing other particular virtues under it.Cf.Plut.Mor.874 e, and inf. §§ 62, 83. Freedom from precipitancy is a knowledge when to give or withhold the mind’s assent to impressions. By wariness they mean a strong presumption against what at the moment seems probable, so as not to be taken in by it.
1.47
Irrefutability is strength in argument so as not to be brought over by it to the opposite side. Earnestness (or absence of frivolity) is a habit of referring presentations to right reason. Knowledge itself they define either as unerring apprehension or as a habit or state which in reception of presentations cannot be shaken by argument. Without the study of dialectic, they say, the wise man cannot guard himself in argument so as never to fall; for it enables him to distinguish between truth and falsehood, and to discriminate what is merely plausible and what is ambiguously expressed, and without it he cannot methodically put questions and give answers.
