Since we think we understand when we know the explanation, and there are four types of explanation (one, what it is to be a thing; one, that if certain things hold it is necessary that this does; another, what initiated the change; and fourth, the aim), all these are proved through the middle term.
Where some people are very wealthy and others have nothing, the result will be either extreme democracy or absolute oligarchy, or despotism will come from either of those excesses.
Every wicked man is in ignorance as to what he ought to do, and from what to abstain, and it is because of error such as this that men become unjust and, in a word, wicked.
We must speak first about the division of land and about those who cultivate it: who should they be and what kind of person? We do not agree with those who have said that property should be communally owned, but we do believe that there should be a friendly arrangement for its common use, and that none of the citizens should be without means of support.
Friends are an aid to the young, to guard them from error; to the elderly, to attend to their wants and to supplement their failing power of action; to those in the prime of life, to assist them to noble deeds.