John Cassian, The Institutes V.13: That we cannot enter the battle of the inner man unless we have been set free from the vice of gluttony

That we cannot enter the battle of the inner man unless we have been set free from the vice of gluttony.

We also ought first to give evidence of our freedom from subjection to the flesh. For “of whom a man is overcome, of the same is he the slave.” And “every one that doeth sin is the slave of sin.” And when the scrutiny of the president of the contest finds that we are stained by no infamy of disgraceful lust, and when we are judged by him not to be slaves of the flesh, and ignoble and unworthy of the Olympic struggle against our vices, then we shall be able to enter the lists against our equals, that is the lusts of the flesh and the motions and disturbances of the soul. For it is impossible for a full belly to make trial of the combat of the inner man: nor is he worthy to be tried in harder battles, who can be overcome in a slight skirmish.