For, in a word, whatever things are natural to men we must not eradicate from them, but rather impose on them limits and suitable times. For man is not to laugh on all occasions because he is a laughing animal, any more than the horse neighs on all occasions because he is a neighing animal. But as rational beings, we are to regulate ourselves suitably, harmoniously relaxing the austerity and over-tension of our serious pursuits, not inharmoniously breaking them up altogether.