Esculapius Fagon! Establish throughout the world the reign of Peruvian bark and of emetics;[807] carry to its perfection the science of those plants which are given to man for prolonging life;[808] observe in your practice, with more exactness and judgment than was ever done before, the influence of climate and weather, the various symptoms and the natural disposition of your patients; treat them in the only way which suits them and by which they can be cured; eradicate the most obscure and inveterate diseases from the human body, which has no secrets for you; but do not attempt the diseases of the mind, for they can never be cured, and leave, therefore, to Corinna, Lesbia, Canidia, Trimalcion, and Carpus, the passion, or rather the mania, they have for quacks. (69.) Astrologers and fortune-tellers, who practise palmistry and calculate nativities, guess at things past by the motion of a sieve, and show undimmed truth in a looking-glass or in a cup of water, are publicly tolerated; such people are, indeed, not without their use; they predict to men theyʼll make their fortune, to girls they shall marry their sweethearts, console those children whose fathers are too long dying, and calm the restlessness of young women married to old men; in a word, they deceive, but not at a very high rate, those who wish to be deceived. (70.) What is to be thought of magic and sorcery? Its theory is very obscure; its principles are vague, uncertain, and visionary, but some facts have been produced which are perplexing, and certified by serious-minded men who were present when they happened, or learned them from other men as reliable as they themselves are. To admit or to deny all these facts seems equally absurd, and I venture to say that in this and in other extraordinary things which deviate from natureʼs laws, a middle course has to be steered between mere credulity and obstinate rejection.[809]