Those who love pleasure, keeping their appetites hot and humid, are indeed sitting by the flesh-pots; for gluttony engenders love of pleasure and many other passions as well. It is the root from which the rest of the passions spring up in vigorous growth, little by little developing as suckers alongside the mother tree, and putting out branches of evil that reach up to the sky. Avarice, anger and dejection are all offshoots of gluttony. For the glutton needs money first of all, so as to satisfy his ever-present desire — even though it never can be satisfied. His anger is inevitably aroused against those who obstruct his acquisition of money… For those who love pleasure, when deprived of it, grow angry and embittered.
St. Neilos the Ascetic, “Ascetic Discourse,” The Philokalia, Vol. 1: