Freedom of choice is not, itself the perfection of liberty. But it helps us take our first step toward freedom or slavery, spontaneity or compulsion. The free man is the one whose choices have given him the power to stand on his own feet and determine his own life according to the higher light and spirit that are in him. The slave, in the spiritual order, is the man whose choices have destroyed all spontaneity in him and have delivered him over, bound hand and foot, to his own compulsions, idiosyncrasies and illusions, so that he never does what he really wants to do, but only what he has to do. His spirit is not in command, and therefore he cannot run his own life. He is commanded by his own weak flesh and its passions––fear, greed, lust, insecurity, untruthfulness, envy, cruelty, servility, and all the rest.
As an explanatory note, Merton is not saying the body is evil when he speaks about “flesh.” The physical is not bad.
Merton, The New Man, 179