John Cassian, Conferences I–X V.26: How when we have got the better of the passion of gluttony we must take pains to gain all the other virtues

How when we have got the better of the passion of gluttony we must take pains to gain all the other virtues.

Wherefore while we are practising fasting and abstinence, we must be careful when we have got the better of the passion of gluttony never to allow our mind to remain empty of the virtues of which we stand in need; but we should the more earnestly fill the inmost recesses of our heart with them for fear lest the spirit of concupiscence should return and find us empty and void of them, and should not be content to secure an entrance there for himself alone, but should bring in with him into our heart this sevenfold incentive of sins and make our last state worse than the first. For the soul which boasts that it has renounced this world with the eight faults that hold sway over it, will afterwards be fouler and more unclean and visited with severer punishments, than it was when formerly it was at home in the world, when it had taken upon itself neither the rules nor the name of monk. For these seven spirits are said to be worse than the first which went forth, for this reason; because the love of good things, i.e., gluttony would not be in itself harmful, were it not that it opened the door to other passions; viz, to fornication, covetousness, anger, dejection, and pride, which are clearly hurtful in themselves to the soul, and domineering over it. And therefore a man will never be able to gain perfect purity, if he hopes to secure it by means of abstinence alone, i.e., bodily fasting, unless he knows that he ought to practise it for this reason that when the flesh is brought low by means of fasting, he may with greater ease enter the lists against other faults, as the flesh has not been habituated to gluttony and surfeiting.