Andreas Cappellanusí [Andrew the Chaplainís]  31 rules for courtly lovers
(developed c. 1185 at the court of  Eleanor of Aquitaine and at the court of her daughter, Marie [Cecily] de Champagne, where Chrťtien de Troyes was writing):

 

  1. The pretext of marriage is no proper excuse against love.
  2. No one who is not jealous can love.
  3. No one can have two loves at once.
  4. Love is always growing or diminishing.
  5. There is no savour in anything obtained by the lover against the belovedís will.
  6. It is not customary for a man to love before puberty.
  7. It is right that the lover should remain unmarried for two years after the death of the beloved.
  8. No one should be deprived of his love without very good reason.
  9. No one can love unless driven on by the prospect of love.
  10. Love is always banished from the home of avarice.
  11. It is not right to love women one would be ashamed to take to wife.
  12. A love divulged rarely lasts.
  13. The true lover desires no embraces from any other than the beloved.
  14. An easy conquest makes love worthless; a difficult one gives it value.
  15. Every lover grows pale at the sight of the beloved.
  16. At the sudden sight of the beloved, the loverís heart quakes.
  17. A new love drives out the old.
  18. Honesty alone makes a person worthy of love.
  19. If love grows less, its decline is swift and it seldom recovers.
  20. A man in love is always fearful.
  21. True jealousy always increases loveís ardour.
  22. A suspicion concerning the beloved increases jealousy and loveís ardour.
  23. A man perturbed by thoughts of love sleeps and eats less.
  24. The belovedís every act ends in thoughts of the lover.
  25. The true lover esteems nothing good except what he thinks will please the beloved.
  26. Love can deny nothing to love.
  27. The lover cannot be sated with the solace of the lover alone.
  28. A slight presumption forces the lover to suspect the worst of the beloved.
  29. He who is fired by too much lust is not likely to love.
  30. The true lover is at all times continually absorbed in imagining the beloved.
  31. Nothing prevents a woman from being loved by two men or a man from being loved by two women.

 

For more information, see The art of courtly love by Andreas Capellanus. With introd., translation, and notes by John Jay Parry (NY: Ungar, 1941).