"There is no part of one’s beliefs about oneself which cannot..." — Peter J. Carroll quote meaning

There is no part of one’s beliefs about oneself which cannot be modified by sufficiently powerful psychological techniques. There is nothing about oneself which cannot be taken away or changed. The proper stimuli can, if correctly applied, turn communists into fascists, saints into devils, the meek into heroes, and vice-versa. There is no sovereign sanctuary within ourseles which represents our real nature. There is nobody at home in the internal fortress. Everything we cherish as our ego, everything we believe in, is just what we have cobbled together out of the accident of our birth and subsequent experiences. With drugs, brainwashing, and other techniques of extreme persuasion, we can quite readily make a man a devotee of a different ideology, the patriot of a different country, or the follower of a different religion.