David Hume's "attack" on personal identity is relevant to this issue. In his A Treatise of Human Nature, Hume wrote:
There are some philosophers, who imagine we are every moment intimately conscious of what we call our SELF; that we feel its existence and its continuance in existence; and are certain, beyond the evidence of a demonstration, both of its perfect identity and simplicity. The strongest sensation, the most violent passion, say they, instead of distracting us from this view, only fix it the more intensely, and make us consider their influence on self either by their pain or pleasure. To attempt a farther proof of this were to weaken its evidence; since no proof can be deriv'd from any fact, of which we are so intimately conscious; nor is there any thing, of which we can be certain, if we doubt of this.
Unluckily all these positive assertions are contrary to that very experience, which is pleaded for them, nor have we any idea of self, after the manner it is here explain'd. For from what impression [i.e., perception] cou'd this idea be deriv'd? ... [S]elf or person is not any one impression, but that to which our several impressions and ideas are suppos'd to have a reference. If any impression gives rise to the idea of self, that
impression must continue invariably the same, thro' the whole course of our lives; since self is suppos'd to exist after that manner. But there is no impression constant and invariable. Pain and pleasure, grief and joy, passions and sensations succeed each other, and never all exist at the same time. It cannot, therefore, be from any of these impressions, or from any other, that the idea of self is deriv'd; and consequently there is no such idea.
What Hume says of the self (or "personal identity") is easily transferable to consciousness: these are not realities that can be directly perceived or fundamentally given. They are, rather, inferred from the very process of perceiving. The inference by which intelligence identifies consciousness is so obvious and inescapable that it may seem as if it were given through direct perception. But it clearly isn't.
Another problem with the Objectivist axiom of consciousness is the vagueness of the term itself, especially within Objectivist writings. Rand tended to use it in several different senses, and it is not always clear, in each of her usages of the term, which sense she means. It would seem that, in this axiom, Rand is using consciousness in the sense of raw sentience. Consciousness, in this sense, is merely the light of awareness. Generally speaking, however, she seems to identify consciousness with intellect or mind. At other times, she identifies it with the self or the will, describing it as "the faculty of awareness" and as "an active process." She even goes so far as identify consciousness with knowledge: if "no knowledge of any kind is possible to man," she opined, then "man is not conscious."
As we shall note in later posts, Rand's tendency to play fast and loose with the term consciousness enables her to equivocate her way to precisely the sort of metaphysical conclusions she desires to reach. While the notion of consciousness may seem "inescapable" (at least via inference) to a foundationalist mindset, only consciousness as raw, passive sentience would be "inescapable" in this sense. After all, surely even Rand would not declare that intellect or knowledge are "axiomatic"! This being so, it is not clear how inferences against idealism or traditional monotheism can be justified using this axiom. But more of this anon.