To a certain extent, Rand was aware of this: it is a theme of much exasperation in her writings. But rather than assuming that the non-rational was a built-in feature (or bug) of human nature, Rand hunted for an explanation for why so many human beings refused to "follow" reason. She found her answer in a contrived and implausible theory of history, where she placed the failure of human rationality squarely on the shoulders of modern philosophers, particularly Kant. "The man who . . . closed the door of philosophy to reason, was Immanuel Kant," she averred. People don't follow reason because philosophers have told them that the human mind is impotent and that they must do as they are told. While Rand and her disciples sometimes add conditions or elaborations to this view, basically that is what it amounts to. The inability of modern philosophers to "validate" reason (by solving the problem of universals) explains why people don't follow "reason" and accept Rand's views.
It was by framing the issue is such extravagently anti-empirical terms that Rand was able to avoid the more obvious conclusion: namely, that human beings don't follow reason because, as Hume explained, reason as at best a method, not an aim or desire; and, morever, the attempt to reason from "is" premises to an "ought" conclusion is invalid. Rand appears not to have understood any of this. She assumed that reason was man's only means of knowledge and from this premise tacitly presumed that human beings must achieve rationality through individual reason. It never occured to her that rationality might be achieved through some other means than individual reasoning, or that there may be other means of knowledge which, in certain circumstances, could prove useful, if not necessary.
In my last post, I quoted Jonathan Haidt insisting that "anyone who values truth should stop worshipping reason." But if reason does not provide "valid" knowledge, what method does? Haidt responds as follows:
We should not expect individuals to produce good, open-minded, truth-seeking reasoning, particularly when self-interest or reputational concerns are in play. But if you put individuals together in the right way, such that some individuals can use their reasoning powers to disconfirm the claims of others, and all individuals feel some common bond or shared fate that allows them interact civilly, you can create a group that ends up producing good reasoning as an emergent property of a social system. This is why it's so important to have intellectual and ideological diversity within any group whose goal is to find truth (such as an intelligence agency or a community of scientists) or to produce good public policy (such as a legislature or advisory board). [The Righteous Mind, 90]
In other words, it turns out that truth is, in many circumstances, a "collective" endeavor: it is a product of individual minds within group dynamics. This is especially the case whenever truth is in the least controversial. Individuals can find truth on their own when that truth is mundane and doesn't violate special agendas or trample upon rooted convictions. But whenever we are confronted with a truth-claim that is controversial, then an individual's judgment is not enough. Open debate involving empirical testing becomes necessary. Where this is impossible truth becomes difficult and consensus impossible.
Rand's faith in the individual's reasoning power is thus unwarranted. That reasoning power may be effective when attacking rival truth claims, but it does not perform well in establishing it's own claims concerning matters of fact. Rand naively took her own mind as the standard of truth and seems to have been oblivious to the need for threshing out truth-claims through debate and critical testing. Although she strongly urged others to "check" their "premises," this was not advice that she herself ever followed. On the contrary, she often responded with intense hostility to criticism. Typical in this respect was her response to Sidney Hook's review of To the New Intellectual. Instead of responding to Hook's criticisms point by point, Rand insisted that Hook should be publicly condemned. Because Leonard Peikoff and Barabara Branden were students of Hook, they were were given a pass; but everyone else, including even Rand's friend John Hospers, were expected to take part in the public condemnation. As Hospers related years later:
Not long after, New York University's philosopher Sidney Hook attacked her in print, and she wanted me to take him on as well. Knowing Sidney, I was disinclined to do this. He already knew about my acquaintance with Ayn, but we had never discussed it further (I hardly ever saw him). Should I now condemn him publicly and destroy a long-standing friendship? I knew that this friendship would be at an end if I condemned him.
Ayn was sure that nothing less than a public condemnation was required to prove to him how much I was devoted to "intellectual objectivity." But she had very little conception of the manners and morals of professional academicians: they can get along well and even be friends, while disagreeing strongly with one another on rather fundamental issues. The philosophic arena was one for the friendly exchange of diverse ideas. But for her, it was a battlefield in which one must endlessly put one's life on the line. I was not willing to risk years of occasional friendly communion with Sidney by condemning him publicly, even if I thought he was mistaken in some of his allegations.
But for Ayn this was a betrayal. It almost cost us our friendship. In the end she attributed my attitude to the misfortune of having been brainwashed by the academic establishment, at least with regard to their code of etiquette.
What Rand failed to appreciate is that the "code of ettiquette" that Hospers writes about is the glue which holds together communities of truth-seeking intellectuals. If everyone began publicly condemning those they disagreed with, that community would break down and all that remain would be a loose assemblages of ideological factions crying anathema against each other.
Rand and her disciples can wax eloquent about "reason" all they like, but at the end of the day they know very little about truth seeking within the limits of human nature. There is a price for denying human nature, and not understanding how truth emerges as the property of a social system is one of them. Yet it's not merely an issue of being ignorant of these basic facts about the search for truth. Objectivism, because of its anti-group biases and its unwillingness to check its own premises, ends up wallowing in irrationality.