Value-judgments are formed ultimately on the basis of a philosophic view of man and life — of oneself, of others, of the universe; such a view, therefore, conditions all one's emotions. If, for example, a man's basic mental set amounts to the idea that he is a helpless incompetent caught in an unknowable jungle, his will affect his value-judgments in every department of life.... By contrast, if a man holds that his mind is efficacious and the universe intelligible, he will form radically different values and, as a result, experience radically different wants, likes, and dislikes [Emphasis added.].
Note the emphasized words. In Objectivism, the ambiguity of words is sometimes used to present two versions of a theory: a strong version and a weak version. The strong version is grossly improbable and cannot to be taken seriously. The weak version, on the other hand, at least enjoys an aura of plausibility. In regard to the Objectivist theory of emotions, the weak theory is the view that one's philosophical views "condition" or "affect" one's value-judgments (and hence, by implication, one's resulting emotions as well). The strong theory, on the other hand, asserts that value-judgments (and the emotions they produce) are entirely (or almost entirely) the product of philosophical views. Which view does Peikoff uphold? Well, in the passage quote above, he seems to lean toward the weaker version, saying that philosophical views only "condition" or "affect," one's value judgments; they don't, presumably then, determine them. But when later we reach the grand conclusion of Peikoff's presentation we are startled to find that following assertion: "Ayn Rand ... holds that man can live exclusively by reason. He can do it because emotions are consequences generated by his conclusions."
Now this assertion depends on the strong version of the theory, and loses whatever logical force it may have without it. For if one's conclusions only "condition" or "affect" one's value-judgments, then, presumably, that would still leave room for other causes, such as innate causes or causes relating to physiological desires. Such causes could affect how one reasons, thereby compromising the claim that "man can live exclusively by reason."
There is yet another problem, and this one appears to be conclusive. It is this: How do individuals go about choosing the philosophical views that determine their value-judgments and their emotions? We know Rand's answer: "Your conscious mind." And if you "default," if your conscious mind doesn't make a concerted effort to form “proper” philosophical views from which rational value-judgments can be deduced, then "you deliver yourself into the power of ideas you do not know you have accepted."
This view of emotions, reason, and consciousness has been refuted by research done in cognitive science, neuroscience, and evolutionary psychology. These sciences have discovered that animals (including human beings) have "primary emotions," which are "innate" and "preorganized" and which depend on limbic system circuitry in the brain. They have discovered that emotions are critical in thinking, so that the notion that "man can live exclusively by reason," when accompanied by the additional notion that "emotions are not tools of cognition," misrepresents what actually happens in cognition. Human beings are not blank slates. Their emotions are not programmed into their “subconscious” by their conscious minds. That view is no more credible than would be an astrological view of emotions. On naturalistic assumptions, emotions are and must be the product of evolution. They are tools of survival, forged in the evolutionary furnace.