Aristotle Principles Quotations

... There must then be a principle of such a kind that its substance is activity.

...The entire preoccupation of the physicist is with things that contain within themselves a principle of movement and rest.

It is clear, then, that wisdom is knowledge having to do with certain principles and causes. But now, since it is this knowledge that we are seeking, we must consider the following point: of what kind of principles and of what kind of causes is wisdom the knowledge?

...virtue is not merely a state in conformity with the right principle, but one that implies the right principle; and the right principle in moral conduct is prudence.

No science ever defends its first principles.

The first principle of all action is leisure.

[the virtues] cannot exist without Prudence. A proof of this is that everyone, even at the present day, in defining Virtue, after saying what disposition it is [i.e. moral virtue] and specifying the things with which it is concerned, adds that it is a disposition determined by the right principle; and the right principle is the principle determined by Prudence.

In [the soul] one part naturally rules, and the other is subject, and the virtue of the ruler we maintain to be different from that of the subject; the one being the virtue of the rational, and the other of the irrational part. Now, it is obvious that the same principle applies generally, and therefore almost all things rule and are ruled according to nature.

The soul has two parts, one rational and the other irrational. Let us now similarly divide the rational part, and let it be assumed that there are two rational faculties, one whereby we contemplate those things whose first principles are invariable, and one whereby we contemplate those things which admit of variation.

[this element], the seat of the appetites and of desire in general, does in a sense participate in principle, as being amenable and obedient to it

There also appears to be another element in the soul, which, though irrational, yet in a manner participates in rational principle.

Again, the male is by nature superior, and the female inferior; and the one rules, and the other is ruled; this principle, of necessity, extends to all mankind.

The only stable principle of government is equality according to proportion, and for every man to enjoy his own.

That which most contributes to the permanence of constitutions is the adaptation of education to the form of government, and yet in our own day this principle is universally neglected. The best laws, though sanctioned by every citizen of the state, will be of no avail unless the young are trained by habit and education in the spirit of the constitution.

Thus then a single harmony orders the composition of the whole...by the mingling of the most contrary principles.

The so-called Pythagoreans, who were the first to take up mathematics, not only advanced this subject, but saturated with it, they fancied that the principles of mathematics were the principles of all things.