...in this way the structure of the universe- I mean, of the heavens and the earth and the whole world- was arranged by one harmony through the blending of the most opposite principles.
A thing chosen always as an end and never as a means we call absolutely final. Now happiness above all else appears to be absolutely final in this sense, since we always choose it for its own sake and never as a means to something else.
We ought to be able to persuade on opposite sides of a question; as also we ought in the case of arguing by syllogism: not that we should practice both, for it is not right to persuade to what is bad; but in order that the bearing of the case may not escape us, and that when another makes an unfair use of these reasonings, we may be able to solve them.
Now, the causes being four, it is the business of the student of nature to know about them all, and if he refers his problems back to all of them, he will assign the "why" in the way proper to his science-the matter, the form, the mover, that for the sake of which.
Anything that we have to learn to do we learn by the actual doing of it; People become builders by building and instrumentalists by playing instruments. Similarily, we become just by performing just acts, temperate by performing temperate ones, brave by performing brave ones.
In bad or corrupted natures the body will often appear to rule over the soul, because they are in an evil and unnatural condition. At all events we may firstly observe in living creatures both a despotical and a constitutional rule; for the soul rules the body with a despotical rule, whereas the intellect rules the appetites with a constitutional and royal rule. And it is clear that the rule of the soul over the body, and of the mind and the rational element over the passionate, is natural and expedient; whereas the equality of the two or the rule of the inferior is always hurtful.
One would have thought that it was even more necessary to limit population than property; and that the limit should be fixed by calculating the chances of mortality in the children, and of sterility in married persons. The neglect of this subject, which in existing states is so common, is a never-failing cause of poverty among the citizens; and poverty is the parent of revolution and crime.
The line has magnitude in one way, the plane in two ways, and the solid in three ways, and beyond these there is no other magnitude because the three are all.
Human good turns out to be activity of soul exhibiting excellence, and if there is more than one sort of excellence, in accordance with the best and most complete.Foroneswallowdoesnot makea summer, nor does one day; and so too one day, or a short time, does not make a man blessed and happy.