1. Philosophy 4610 Philosophy of Mind Week 11: The Problem of Consciousness

2. AI and Consciousness: Recap and Transition  We considered the problem of whether a computer could actually be intelligent or thinking  For many people, the biggest obstacle to artificial intelligence is the question of consciousness: could a computer actually be conscious or (self)-aware?  How could we tell if it were conscious?

3. The problem of consciousness  In addition to all of our behavior and functioning, each of us is also conscious – we have experiences, sensations, thoughts, etc. that we can know from a first-person perspective.  The problem of explaining how this is possible is one of the most difficult in philosophy today.

4. Defining Consciousness: “What It’s Like”  “But no matter how the forms may vary, the fact that an organism has conscious experience at all means, basically, that there is something it is like to be that organism.” (p. 219)  According to Nagel, we can say that X is conscious if there is something that it’s like to be X.  Does this seem like an adequate definition? What sorts of things satisfy the formula?

5. Defining Consciousness: The “Subjective Quality of Experience”  According to Nagel, if there is something that it is like to be me – if I am conscious – then our experience has a subjective quality (what it is like for me).  Other philosophers have used the term “qualia” (singular: quale) to refer to subjective qualities of experience  Example: redness of experienced red, taste of pizza, sound of foghorn

6. Nagel and the problem of explaining consciousness  According to Nagel, the subjective properties of experience, or qualia, will be very difficult to explain from a scientific point of view  The reason is that scientific explanations are objective (third-person) explanations. But qualia or subjective qualities are known only from a subjective (first-person) point of view.

7. Scientific Explanation: the ‘view from nowhere’  Scientific explanations normally work by abstracting from or eliminating our particular points of view.  The way we explain phenomena such as lightning, or water, is to abstract from our own particular point of view to gain access to what we could see from any point of view.  But in the case of consciousness, this is impossible. For if we abstract from our own point of view, we lose the phenomenon itself.

8. Example: What it’s like to be a bat  There is something that it’s like to be a bat  But what it is like to be a bat may be very difficult to understand  Usually, we understand someone else’s experience by analogy with our own. But this is very difficult in the case of the bat.

9. Nagel: The difficulty of understanding bat-experience  I have said that the essence of the belief that bats have experience is that there is something that it is like to be a bat. Now we know that most bats … perceive the external world primarily by means of echolocation …Their brains are designed to correlate the outgoing impulses with the subsequent echoes, and the information thus acquired enables bats to make precise determinations of distance, size, shape, motion, and texture … But bat sonar, though clearly a form of perception, is not similar in its operation to any sense that we possess, and there is no reason to suppose that it is subjectively like anything we can experience or imagine.” (p. 220).

10. The problem of consciousness  According to Nagel, it is impossible or almost impossible to give a physicalistic explanation of the bat’s consciousness  How might we try giving a physicalist explanation? A functionalist explanation?  What (if anything) would be left out of such an explanation?

11. Nagel against physicalism Nagel against physicalism  According to Nagel, because of this problem, there is at present no hope for a physicalist explanation of consciousness.  This doesn’t necessarily mean that dualism is true – just that consciousness is extremely difficult to explain in physicalist terms.

12. Can we hope to explain consciousness?  “At the present time the status of physicalism is similar to that which the hypothesis that matter is energy would have had if uttered by a pre-Socratic philosopher. We do not have the beginnings of a conception of how it might be true.” (p. 224).  Is the problem really as bad as Nagel says? What might help?