Reason is an attribute of the individual. There is no such thing as a collective mind or brain. Thought is a process that must be initiated and directed at each step by the choice of one man, the thinker. Only an individual qua individual can perceive, abstract, define, connect. Here again we are dealing with an empirical matter. The same observations which reveal that consciousness is an attribute of certain living organisms reveal that it belongs to separate organisms. And, in regard to man’s consciousness, observation is what reveals that it is volitional.
The point is broader than consciousness. Entity, as we have seen, is the primary “category.” Only entities can act— and to be an entity is to be an individual. A group of men is a derivative phenomenon; it is not an entity, but a collection of them, an aggregate of individuals. “All the functions of body and spirit,” writes Ayn Rand, “are private. They cannot be shared or transferred.” One cannot think for or through another person any more than one can breathe or digest food for him. Each man’s brain, like his lungs and stomach, is his alone to use.
Men can learn from other men, an ability that is invaluable in the struggle for survival. But learning is an active process; others do not …
Read the rest in Objectivism: The Philosophy of Ayn Rand.