How do neurobiological processes in the brain cause consciousness? I think this is the most important question in the biological sciences today. Two related questions: Where exactly is consciousness realized in the brain and how does it function causally in our behavior? Antonio Damasio is one of the leading workers in the field of consciousness research, and after having written a number of books on related problems, in Self Comes to Mind he addresses the problem of consciousness directly. He does not claim to have solved it but he believes that he has made advances and pointed in the right direction for a solution.
What exactly is consciousness? There are a number of senses of the word in ordinary speech, but there is one that is most important for philosophy and science: consciousness consists of qualitative, subjective states of feeling or sentience or awareness. These typically begin when we awake from a dreamless sleep and they go on until we fall asleep again or otherwise become unconscious. Dreams are a form of consciousness. Consciousness, in short, is a matter of the qualitative experiences that we have. To understand qualitativeness, think of the difference between drinking beer, listening to music, and thinking about your income tax. Each experience has a distinct quality.
Because of this qualitative character all conscious states are essentially subjective in the sense that they exist only as experienced by a subject—human or animal. The problem of consciousness can now be stated somewhat more precisely: How does the brain produce qualitative subjectivity? How does it get us over the hump from the objective third-person character of neuron firings to the subjective first-person feelings we have when we are conscious?
There is so much confusion surrounding the notions of objectivity and subjectivity that I need to say a word to clarify them. In one sense, the objective/subjective distinction is about claims to knowledge. I call this the epistemic sense. A claim is said to be objective if its truth or falsity can be settled as a matter of fact independently of anybody’s attitudes, feelings, or evaluations; it is subjective if it cannot. For example, the claim that Van Gogh died in France is epistemically objective. But the claim that Van Gogh was a better painter than Gauguin is, as they say, a matter of subjective opinion. It is epistemically subjective.
In another sense, the objective/subjective distinction is about modes of existence. I call this the ontological sense. An entity has an objective ontology if its existence does not depend on being experienced by a human or animal subject; otherwise it is subjective. For example, mountains, molecules, and tectonic…
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