The desire for the pleasures of the senses is not necessary—one can live on gruel and water, one does not die without sex—but it is perfectly natural. As soon, however, as one starts to want not just something pleasant to drink but a particular vintage of a particular wine, and not just sexual pleasure but sexual pleasure with a particular person, one is no longer listening to the body, but to the mind; an obsession is developing whose inevitable consequence is displeasure that the desired object is missing or anxiety that it might be.
