Jeremy Corbyn says he is very excited about his campaign to become Labour leader because lots of young people are becoming involved in it, which ‘must be a good thing’. Aristotle (384–322 bc) would have his doubts.

In his Art of Rhetoric, Aristotle pinpoints the sorts of thing that can be said on a large number of topics which will encourage your audience to agree with you. One such topic is the character of the young.

In general, he says, the young are pleasure-loving, impulsive and optimistic. Of the desires of the body, he says, they are keenest on sex, and powerless against its demands. But since they are keen rather than determined, their lust is quickly satisfied. They are impulsive, hot-tempered and follow it up with action. Because being admired is very important to them, they cannot bear to be belittled, and get angry if they think they have been wronged.

They are not especially interested in money, because they have never needed it; they are not cynical, never having experienced much wickedness; they are naive, never having been deceived very often; and optimistic, never having experienced much in the way of failure.

For the most part, Aristotle continues, they live in hope, ‘since hope is for the future, but remembrance for what has passed, and at the beginning of life, the past is short but the future long’. So because they easily hope, they are easily deceived, but they are more courageous too: for their passion prevents them fearing, while their hope inspires them with confidence. They also prefer to do what is fine rather than what is in their interest, since they live by character rather than calculation, and so are inexperienced in making judgements to their own advantage. Thinking they know everything, they are obstinate; but they are inclined to pity because they judge others as they do themselves and assume all men are honest.

All rather like the charming Mr Corbyn himself. If only the world of politics were so innocent.