Let your Mercury—reason—govern you against all enticements, apparent delights and pleasing temptations from within or without. You can do this if you will. “A father does not dote on his daughter, nor a brother on his sister”: a father does not lust after his own daughter, nor a brother after his sister. Why? Because it is unnatural, unlawful and unfitting. If he is sickly, weak or deformed, let him think about his deformities, faults and infirmities. If in debt, let him ponder how to pay it; if in danger, let him seek to avoid it. If he has a lawsuit or other business, he would do well to leave his love affairs alone and attend to it, working at his calling, whatever it may be.

But if he cannot relieve himself in this way, let him still reflect prudently on both their circumstances. If their ages are unequal, she young and he old, what an unsuitable match it must be, an uneven yoke! How absurd and indecent for an old, bald, crooked-nosed scoundrel to marry a young woman, as Lycinus in Lucian told Timolaus. How odious to see an old lecher! What should a bald fellow do with a comb, a mute dotard with a pipe, a blind man with a mirror—or you with such a wife? How absurd for a young man to marry an old woman for a share of property.

But suppose her age, birth and wealth are equal to his, and her other qualities correspond. He wishes to be joined in marriage, which is an honourable condition—but for what reasons? Her beauty, presumably, and her bodily grace: that is usually the chief attraction. She is a perfect beauty, in his eyes at least, “to whom the Paphian goddess gave beauty, and the Graces grace.” But do other men say as much? Or is his judgment mistaken?

Our eyes and wandering senses deceive us; With reason overpowered, they lie.

Our eyes and other senses commonly deceive us. Perhaps, even to you, on closer examination or after a short absence, she is not as beautiful as she seems. “Some things appear to be what they are not.” Compare her with another woman standing beside her; that is a touchstone for the test. Compare hand with hand, body with body, face with face, eye with eye, nose with nose, neck with neck, and so on. Examine each part separately, then all together, in every posture and different position, and tell me how you like her.

Perhaps it is her clothes, not she, that are so beautiful; put another woman in them and she will seem just as beautiful. As the poet therefore prescribes, separate her from her clothes. Imagine seeing her in a poor beggar’s dress, or in some old, shaggy, unfashionable outfit, dirty linen and coarse clothing, smeared with soot and grime, scented with opopanax, sagapenum, asafoetida or other such foul-smelling gums, filthy and engaged in some unseemly activity.

Or imagine her in the condition in which the physician Brasavola found his patient Malatasta after a dose of hellebore he had prescribed: “With his hands on the ground and his anus raised towards the sky—as though one were seeing that Socratic Aristophanes who, drawing geometrical figures on the ground, seemed to be gathering truffles—he squirted black bile onto a white wall, and so befouled the whole room and himself that,” and so forth. Utterly fouled, or worse: if you saw her like this, I say, would you love her as you do?

Suppose you saw her on a frosty morning, in cold weather, in some fit of passion or disturbance of mind, weeping or raging, wrinkled and ugly to look at. A woman who, with a composed expression, often seems so lovely and delightful, “so pretty in form,” may, merely by laughing or smiling, make an ugly sparrow-mouthed face and reveal uneven, loathsome, rotten, dirty teeth.

She has dark skin, gouty legs and a deformed, crooked body beneath a fine dress. Perhaps, for all her costly headdresses, she is bald; and although she seems so beautiful in darkness, by candlelight or at a distance, as Callicratidas observed in Lucian, “if you saw her close up or in the morning, she would seem uglier than a beast.” “If you carefully consider what comes out through the mouth, nostrils and other passages of the body, you have never seen a viler dunghill.”

Follow my advice: see her undressed; see her, if possible, without her finery, “stripped of her borrowed colours.” Perhaps she is like Aesop’s jay or Pliny’s blister beetles: she will be repulsive and ridiculous; you will not bear to look at her. Or imagine seeing her ill, pale, wasting away, on her deathbed, skin and bones, or already dead: “She whose embrace was most delightful,” as Bernard says, “will be horrible to look at.”

She who usually smells sweet now stinks, with no sweet scent.

Like a posy, she smells sweet and is fresh and beautiful one day, but dried up, withered and stinking another. Beautiful Nireus, so greatly admired by Homer, once dead is uglier than Thersites; and Solomon, dead, is as ugly as Marcolphus. Your lovely mistress, who was once “Charis, dearer than one’s eyes,” dearer to you than your own eyes, once ill or dead is

Judged fouler than foul mire,

worse than any dirt or dunghill. Her embraces were never so welcome as her appearance is now terrible. You would do better to look at a Gorgon’s head than at Helen’s corpse.

Some think that seeing a woman naked can itself change a man’s affection. It is worth considering, says the Frenchman Montaigne in his Essays, that the most skilful masters of amorous play prescribe a full view of the body as a remedy for sexual passions. The poet suggests as much: