Appetites and pleasures which are in accordance with nature are not reprehensible, since they are a necessary consequence of natural appetency. For our ordinary food, whether we wish it or not, naturally produces pleasure, since it satisfies the hunger which precedes a meal. Drink: also produces pleasure, since it relieves the discomfort of thirst; so does sleep, since it renews the strength expended in our waking hours; and so, too, do all our other natural functions necessary for maintaining life and conducive to the acquisition of virtue.

St Maximos the Confessor, Various Texts on Theology, the Divine Economy, and Virtue and Vice