Chapter 3: Exactness not permitted by subject nor to be expected by student, who needs experience and training.

We must be content if we can attain to so much precision in our statement as the subject before us admits of; for the same degree of accuracy is no more to be expected in all kinds of reasoning than in all kinds of handicraft.

Now the things that are noble and just (with which Politics deals) are so various and so uncertain, that some think these are merely conventional and not natural distinctions.

There is a similar uncertainty also about what is good, because good things often do people harm: men have before now been ruined by wealth, and have lost their lives through courage.

Our subject, then, and our data being of this nature, we must be content if we can indicate the truth roughly and in outline, and if, in dealing with matters that are not amenable to immutable laws, and reasoning from premises that are but probable, we can arrive at probable conclusions.

The reader, on his part, should take each of my statements in the same spirit; for it is the mark of an educated man to require, in each kind of inquiry, just so much exactness as the subject admits of: it is equally absurd to accept probable reasoning from a mathematician, and to demand scientific proof from an orator.

But each man can form a judgment about what he knows, and is called “a good judge” of that—of any special matter when he has received a special education therein, “a good judge” (without any qualifying epithet) when he has received a universal education. And hence a young man is not qualified to be a student of Politics; for he lacks experience of the affairs of life, which form the data and the subject-matter of Politics.

Further, since he is apt to be swayed by his feelings, he will derive no benefit from a study whose aim is not speculative but practical.

But in this respect young in character counts the same as young in years; for the young man’s disqualification is not a matter of time, but is due to the fact that feeling rules his life and directs all his desires. Men of this character turn the knowledge they get to no account in practice, as we see with those we call incontinent; but those who direct their desires and actions by reason will gain much profit from the knowledge of these matters.

So much then by way of preface as to the student, and the spirit in which he must accept what we say, and the object which we propose to ourselves.