29. Of the desires, some are natural and necessary, some are natural but not necessary, and some are neither natural nor necessary, but owe their existence to vain imagination.

Alternate Translations: Bailey: Among desires some are natural (and necessary, some natural) but not necessary, and others neither natural nor necessary, but due to idle imagination.

Vatican Saying 20: Of our desires some are natural and necessary, others are natural but not necessary; and others are neither natural nor necessary, but are due to groundless opinion.

NewEpicurean Commentary: You will more easily keep reason in charge of your desires if you remember that some desires are both natural and necessary, some are natural but not necessary, and some are neither natural nor necessary but purely the result of illusions that we pick up from other people.