The Certainty Principle
The Uncertainty Principle in physics comes as no surprise to a skeptic. We can’t know the position and velocity of a subatomic particle—so what? We can’t know a lot of things, including the position and velocity of an elephant. We think we can know that—or we think it when we are not thinking—but elementary reflection quickly convinces us that no such knowledge is possible for human beings. Newton’s physics is as uncertain as Heisenberg’s once we get critical about knowledge. Knowledge is basically an effect of the world, and the world does not affect us in such a way as to reveal its full nature. That should not surprise anyone according to the skeptic. Everything is subject the Uncertainty Principle—the truism that we can’t be certain of anything.
But wait: is that principle universally true? Can’t I know the intensity and quality of my present sensations? It is not that knowledge of the one automatically rules out knowledge of the other, or that there is some insuperable barrier to knowledge here. Indeed, I can be certain of the properties of my consciousness, so that skepticism gets no purchase: it is laid out before me, fully and transparently. True, the unconscious is subject to an uncertainty principle, like the body, but the conscious mind is subject to a Certainty Principle—the principle, namely, that I know with certainty the present state of my consciousness. I can’t know my brain in this way, but I can know the consciousness that depends on my brain. So consciousness possesses a remarkable epistemic property—it admits of certain knowledge. The physical world is subject to the Uncertainty Principle, both in physics and more generally, but the mental world is subject to a Certainty Principle. Amazing! How could anything in reality produce effects on us that guarantee knowledge of that thing? How does consciousness manage to convey its inner nature so perfectly? That seems contrary to the very nature of knowledge and yet it is apparently true. It even has an air of paradox about it—real yet fully known.
It doesn’t normally strike us that way because we are so familiar with consciousness, but a simple thought experiment makes us see how strange the situation really is. Suppose we were brought up knowing all about quantum theory: Heisenberg’s Uncertainty Principle is second nature to us, as familiar as elementary arithmetic. Moreover, our teachers have placed this principle in the context of general skepticism: we are thoroughly versed in skeptical thought and take it for granted in our daily lives. Epistemic limits are bread and butter to us. However, no one has ever said anything to us about consciousness—that subject has been off limits, possibly to discourage undue introspection. But this has not prevented a group of renegade thinkers from investigating the topic: they want to find out the truth about this aspect of nature. They have made some interesting discoveries about consciousness such as that it has intentionality and subjectivity and that it varies in certain ways with facts about the physical world. So far, though, no one has broached the question of the epistemology of consciousness, so ingrained is the acceptance of epistemic modesty. But one intrepid thinker takes the revolutionary step of questioning the general belief in Uncertainty and announces that there is something in the world that admits of complete Certainty. This is shocking, maybe even paradoxical, because the relation between reality and our epistemic faculties is generally believed not to admit of such a thing, and yet upon examination it turns out that consciousness is an exception to the general rule. Naturally the scientific world is in an uproar, but people have to admit that this brave thinker is onto something: the Certainty Principle gradually gains acceptance, despite some initial resistance. We have discovered that nature contains pockets that can be known with certainty—we can even know the intensity and quality of a sensation simultaneously! The Certainty Principle is added to the Uncertainty Principle as a pillar of science—though some people find it hard to accept the new paradigm, stubbornly insisting that it is simply not possible for any knowledge to escape the Uncertainty build into all human knowledge (so called). There must be some error in the reasoning that leads to that conclusion, or experiments are cited that purport to show that contrary to appearances error can creep into self-knowledge. Actually whenever someone takes himself to know both the intensity and quality of a sensation he is always a bit wrong about one of these properties. However, this is a minority position, with most people accepting the newly discovered Certainty Principle. A Nobel Prize eventually ensues.