Book VI

There are some things, my most excellent Liberalis, which lie completely outside of our actual life, and which we only inquire into in order to exercise our intellects, while others both give us pleasure while we are discovering them, and are of use when discovered. I will place all these in your hands; you, at your own discretion, may order them either to be investigated thoroughly, or to be reserved, and be used as agreeable interludes. Something will be gained even by those which you dismiss at once, for it is advantageous even to know what subjects are not worth learning. I shall be guided, therefore, by your face: according to its expression, I shall deal with some questions at greater length, and drive others out of court, and put an end to them at once.