Book 1
11.5
Now, of desires some are irrational, others rational. I call irrational all those that are not the result of any assumption.There is no consideration or definite theory (Jebb, Welldon) of the results that may follow. The desires arise without anything of the kind; they simply come. Such are all those which are called natural; for instance, those which come into existence through the body—such as the desire of food, thirst, hunger, the desire of such and such food in particular; the desires connected with taste, sexual pleasures, in a word, with touch, smell, hearing, and sight. I call those desires rational which are due to our being convinced; for there are many things which we desire to see or acquire when we have heard them spoken of and are convinced that they are pleasant.
