Our common sense notion of consciousness is that it is a thing—I have a mind and my mind is perceiving and thinking. Much of philosophy has been spent trying to discover what consciousness is or simply assuming that it already understands what it is. However, Edmund Husserl, building on the work of Kant, took issue with the standard notion of consciousness as a thing-in-itself.
The short of it is that Husserl said that when we examine consciousness we do not find a metaphysical substance. He agreed with Hume, Kant, and Kierkegaard on that. Husserl said that we detect that which consciousness is aware of but not consciousness itself. What defines consciousness is not a subject (we have no impression of it as Hume pointed out) but the objects of consciousness—consciousness always takes an object. This was Husserl’s doctrine of intentionality. Consciousness “points to” something and all we really “see” is what it points to. I liken it to how we don’t see the eye, we only see what the eye sees. Consciousness is completely transparent in that way. Husserl believed that armed with this understanding we can begin to discover essences because we can leave out the stumbling block of trying to describe the substance of consciousness and can go “to the things themselves.”
The metaphysical question here is whether consciousness can be considered to be any kind of substance—a thing-in-itself. Does consciousness depend on nothing else for its existence as Descartes believed? Can consciousness be predicated (part of Aristotle’s definition of substance) like other objects such as a tree, i.e. it is tall, has leaves, etc.? My understanding of Husserl’s argument is that because consciousness exists only in the mode of intention—taking an object—then it cannot be considered a substance or a thing-in-itself. Thinking is nothing unless it is thinking about something, and only in the action of thinking about something does consciousness exist. One could say that consciousness is never a noun, only a verb. Thus, it is not something that is concrete. In fact, nothing in consciousness can be considered complete because awareness is always incomplete and sketchy. The word Husserl uses is “adumbration.” Our thoughts are not crystal clear, they are adumbrations “surrounded by a halo of indeterminacies which could themselves be filled out only through successive adumbrations.” Our ideas are constantly in flux reactining continually in response to new ideas and new information. Thus, in no way can consciousness be considered a concrete thing-in-itself that can be defined independently. This does not mean that consciousness is not real, but it means that consciousness is not a concrete object such as a tree. I don’t think this reality leads us into the morass of postmodernism but it does mean we can’t go back to a pre-Kantian notion of objective consciousness as I accuse the analyticals of doing.
Some have countered that okay, consciousness is not a thing-in-itself but it is a “state the brain can be in.” I suspect that Husserl would not even agree with that notion because calling it a “state” is to still give it a kind of substance; but it is hard to pin Husserl down on something like that. It also requires a much longer discussion of modality than I want to get into here.
I should add that Husserl’s views of consciousness are why I am so skeptical of neuro-this and neuro-that trying to tell us what consciousness is, because the most it could ever show are the objects and effects of consciousness, if that, and the field seems to fundamentally not grasp that it can’t do what it tries to do. Neuroscience claims to be “finding the neurocorrelates of consciousness” when they hook up a person to a machine and lights flash on their monitor. I agree that that is what neuroscience attempts. I will use the Turing Test to illustrate my problem with it. Let’s say we have a machine that lights up when we hook it up to a person. What do the lights tell us? Like Turing’s machine—we see only the result, we cannot tell what is at the other end causing the result. A glitch in the machine could cause the same light pattern on the monitor—is that consciousness? How would be able to tell? Another illustration is Wittgenstein’s “beetle” thought experiment. If someone says “beetle” to describe the contents of a box they are holding but we cannot see into, what does that tell us? Do we, in hearing “beetle,” now know what is in the box? Can we be sure that what they mean by “beetle” is what we mean by “beetle?” And how would we be able to tell if they are telling the truth? If someone says “beetle” we can be sure only that someone has said “beetle” not what is actually in the box. What these two thought experiments illustrate is that effects are not to be confused with causes. The lights on a machine tell us only that there are lights on a machine. It does not tell us “aha! consciousness is found!” anymore than we could say we know that is a human (Turing) or there is actually a beetle in the box (Wittgenstein).
Consciousness still eludes objectification and probably always will. It is not a thing-in-itself.