Kitap 5
1.29
As making for discovery he left in the Topics and Methodics a number of propositions, whereby the student can be well supplied with probable arguments for the solution of problems. As an aid to judgement he left the Prior and Posterior Analytics. By the Prior Analytics the premisses are judged, by the Posterior the process of inference is tested. For practical use there are the precepts on controversy and the works dealing with question and answer, with sophistical fallacies, syllogisms and the like. The test of truth which he put forward was sensation in the sphere of objects actually presented, but in the sphere of morals dealing with the state, the household and the laws, it was reason.
1.30
The one ethical end he held to be the exercise of virtue in a completed life. And happiness he maintained to be made up of goods of three sorts: goods of the soul, which indeed he designates as of the highest value; in the second place bodily goods, health and strength, beauty and the like; and thirdly external goods, such as wealth, good birth, reputation and the like. And he regarded virtue as not of itself sufficient to ensure happiness; bodily goods and external goods were also necessary, for the wise man would be miserable if he lived in the midst of pains, poverty, and similar circumstances. Vice, however, is sufficient in itself to secure misery, even if it be ever so abundantly furnished with corporeal and external goods.
1.31
He held that the virtues are not mutually interdependent. For a man might be prudent, or again just, and at the same time profligate and unable to control his passions. He said too that the wise man was not exempt from all passions, but indulged them in moderation.