The second strong hint comes from George Santayana, who, in his demolishment of Moore's ethical philosophy (as limned by Russell) , noted that all arguments for morality committed the ad hominem fallacy:
That good is not an intrinsic or primary quality, but relative and adventitious, is clearly betrayed by Mr.Russell's own way of arguing, whenever he approaches some concrete ethical question. For instance, to show that the good is not pleasure, he can avowedly do nothing but appeal "to ethical judgments with which almost every one would agree." He repeats, in effect, Plato's argument about the life of the oyster, having pleasure with no knowledge. Imagine such mindless pleasure, as intense and prolonged as you please, and would you choose it? Is it your good? Here the British reader, like the blushing Greek youth, is expected to answer instinctively, No! It is an argumentum ad hominem (and there can be no other kind of argument in ethics); but the man who gives the required answer does so not because the answer is self-evident, which it is not, but because he is the required sort of man. He is shocked at the idea of resembling an oyster. Yet changeless pleasure, without memory or reflection, without the wearisome intermixture of arbitrary images, is just what the mystic, the voluptuary, and perhaps the oyster find to be good.
The third strong hint was noticed, among others, by Pareto when, in his mammoth work investigating the relation between conduct and belief, Trattato di sociologia generale, he noticed that most moral philosophies were devoid of specific ethical content. For this reason (among others), our conduct could not be governed by a moral philosophy, since the purpose of moral philosophy is not to provide guidance (how could it when little or no specific conduct can be deduced from it?), but to coddle and flatter human sentiments. (For Pareto's analysis of Kant's ethics, see here.)
Scientific experiments on human behavior only serve to reinforce Pareto's hypothesis. What they demonstrate is that human beings develop a sense for morality well before they are ever exposed, or could even understand, abstract moral philosophy. As Jean Piaget noted about justice, "The sense of justice, though naturally capable of being reinforced by precepts and practical examples of the adult, is largely independent of those influences, and requires nothing more of its development than the mutual respect and solidarity which holds among the children themselves." [Quoted by J. Q. Wilson in The Moral Sense, 58] So if children have a moral sense before they are exposed to philosophical morality, this suggests that the moral theory comes before the philosophy. Moral behavior and a sense for morality is noted even in toddlers.
When we apply these insights to the Objectivist ethics, it is difficult to avoid the conclusion that Rand's moral system, like the moral systems of so many other philosophers, consists almost entirely of the rationalization of moral ideals that existed well before any set of abstractions was built around them. The equivocations, ad hominem attacks, and intimidation tactics which Rand used to give her ethics persuasive force all provide additional evidence that it is sheer causistry, rather than sober elaboration of eternal truths about the human condition. Yet the strongest evidence of all consists in the rather surprising fact, unnoticed and evaded by most Objectivists, that Rand's ethical philosophy is devoid of specific content, and that no one could actually use it as a guide for behavior. As Nathaniel Branden noted, "The great, glaring gap in just about all ethical systems of which I have knowledge, even when many of the particular values and virtues they advocate may be laudable, is the absence of a technology to assist people in getting there, an effective means for acquiring these values and virtues, a realistic path people can follow.... Ayn Rand’s work [contains] an ethical philosophy with a great vision of human possibilities, but no technology to help people get there."
Lacking a "technology" means that no Objectivist, including Rand herself, actually follows the Objectivist morality. They do not follow it because it is just not possible: Rand's ethical system is far too general and abstract to apply to all the many unique situations the individual confronts in everyday life. Now if it is argued that the Objectivist ethics is not intended to be applicable to every situation or to cover every detail of human conduct, that, on the contrary, it merely covers the most important "essentials," such as whether one should be honest, rational, productive, and so on, even with these qualifications added to the analysis, serious doubts arise as to whether the Objectivist ethics offers any real, practical guidance: for all these virtues, although given out as "absolutes," are, as it turns out, merely "contextual" in nature, which means they are, in fact, not always applicable (it depends on the "context"). Unfortunately, Rand provided no technology for determining context. Other than a few vague hints, Rand and her disciples never bothered to explain how to distinguish those contexts in which such virtues as honesty, productivity, integrity, and rationality were absolutes from those contexts in which these fine virtues no longer applied. The huge amount of ambiguity which characterizes the Objectivist ethics renders it, for most practical purposes, inefficacious and useless. An enormous amount of futile argumentation and wasted scribbling could have been avoided if Rand had just told her followers, Behave in a way pleasing to me, because that, in the final analysis, is what the Objectivist ethics amounts to.
Now consider the irrationality of propagating an ethical system that doesn't give any real, practical guidance. How is that to be explained? Why would any philosopher, especially a philosopher who made so much virtuous noise on behalf of "reason," do such a thing? If Rand's ethics were intended (as Rand insisted) to provide a manual for survival, how come the manual doesn't come with any instructions? The most plausible explanation is that the Objectivist ethics is a rationalization of Rand's own moral preferences, many of which were the product of her own, private cognitive unconscious, which she misidentified with "reason" and objective truth. Any ethics, whether Objectivist, Kantian, utilitarian, etc. which provides little if any guidance in everyday life is almost certainly a product of rationalization. In the majority of cases, moral conduct primarily arieses, not from abstract principles, but from the "tacit" knowledge of the cognitive unconscious guided by an intuitive moral sense.