Pervasiveness of Rationalization in Human Thought. Studies of unconscious brain processes (sometimes called "alien subroutines") reveals a curious phenomenon: the conscious mind often seeks to rationalize what emerges from the unconscious. As David Eagleman explains:
Not only do we run alien subroutines [i.e., unconscious processes]; we also justify them. We have ways of retrospectively telling stories about our actions as though the actions were always our [i.e., our conscious mind's] idea.... We are constantly fabricating and telling stories about the alien processes running under the hood.
To bring the sort of fabrication to light, we need only look at another experiment with split-brain patients.... In 1978, researchers Michael Gazzaniga and Joseph LeDoux flashed a picture of a chicken claw to the left hemisphere of a split-brain patient and a picture of a snowy scene to his right hemisphere. The patient was then asked to point at cards that represented what he had just seen. His right hand pointed to a card with a chicken, and his left hand pointed to a card with a snow shovel. The experimenters asked him why he pointed to a shovel. Recall that his left hemisphere (the one with the capacity for language), had information only about a chicken, and nothing else. But the left hemisphere, without missing a beat, fabricated a story: "Oh, that's simple. The chicken claw goes with the chicken, and you need a shovel to clean out the chicken shed." When one part of the brain makes a choice, other parts can quickly invent a story to explain why. If you show the command "Walk" to the right hemisphere (the one without language), the patient will get up and start walking. If you stop him and ask why he's leaving, his left hemisphere, cooking up an answer, will say something like "I was going to get a drink of water."
The chicken/shovel experiment led Gazzinga and LeDoux to conclude that the left hemisphere acts as an "interpreter," watching the actions and behaviors of the body and assigning a coherent narrative to these events. And the left hemisphere works this way even in normal, intact brains. Hidden programs drive actions, and the left hemisphere makes justifications. This idea of retrospective storytelling suggest that we come to know our own attitudes and emotions, at least partially, by inferring them from observations of our own behavior. As Gazzinga put it, "These findings all suggest that the interpretative mechanism of the left hemisphere is always hard at work, seeking the meaning of events. It is constantly looking for order and reason, even when there is none -- which leads it continually to make mistakes." [Incognito, 133-134]
Gazzinga and LeDoux's findings do not represent some sort of anomaly, applicable to only split-brain patients. Researchers continually run across subjects who are obviously inventing stories about something they know little about. Whether man is in fact a rational animal, as Rand and her disciples always insisted, is doubtful; but he is very much a rationalizing animal. However, this leads to a problem: if rationalization is pervasive in human thought, doesn't this suggest that all human thought, including the thought that rationalization is pervasive, is itself a rationalization? If rationalization is pervasive, how can one know the truth?
Human beings have developed a number of counter-measures to circumvent the strong tendency to rationalization. The most powerful of these counter-measures is openness to criticism. While the individual may not be very good at catching himself in that act of rationalization, he's often pretty shrewd when it comes to detecting it in others. Hence the development of institutions in science and scholarship that use peer review to arrive at truth. Our justice system has also developed institutions to wrestle with the problems of innate bias and rationalization. The old saw that no man should be a judge in his own cause reflects centuries of human experience concerning the question of whether people can be trusted to be objective about issues involving their own interest. Their objectivity is not only compromised by vested interests, but by the tendency to unwittingly rationalize.
While Rand may have been able to detect rationalization in others (which is not very hard), she appears to have been incapable of detecting it in herself. Indeed, the biographical evidence strongly suggests that Rand was intensely committed to a vision of herself that excluded the possibility of rationalization, bias, or any other form of "irrationality." Rand once boasted that she had never experienced an emotion that clashed with her reason for more than a day [Sciabarra, ARRR, 185-186] -- a boast which raises serious questions about Rand's own objectivity and the validity of her introspections. Since the human brain is not a unified system, the only way to explain Rand's claim is that she rationalized her emotions so that they fit the artificial, self-imposed narrative that she wished to construct around her life. Rand appears to have been strongly invested in the notion that she, unlike many other people, knew how to think rationally, and this meant she was right and everyone who disagreed her was wrong (and perhaps evil as well). This frame of mind closed Rand off to effective criticism and shut up her mind in a series of self-reinforcing loops. Those most prone to rationalization are precisely those most invested in the belief that they are free of such intellectual vices. The most effective counter-measures to rationalization are humility about one's own mind and openness to criticism from others. Rand was strongly biased against either of these counter-measures, and hence enjoyed little chance of escaping from the mind's strong tendency toward telling stories rather than embracing truth.