The reading by Singer seems to place a significant ethical burden upon people, one which many may feel as unfairly demanding.  Read the following excerpts from an imaginary dialogue by Raymond Smullyan in which God attempts to address this issue, then answer the following in 800 words.


1. All phenomena in nature seem to be either caused by the preceding state of nature (a net force causes a resulting acceleration in the particle it acts on), are random (whether or not a particular photon passes through a glass plate or is reflected by the glass), or are some combination of the two (the position of an electron in an atom).  But where is there room in all of this for free will?  If a physical phenomenon is determined by the preceding state of nature, it cannot be affected by human choice and if a physical phenomenon is random like a roll of dice, it too cannot be affected by human choice.  And yet, we feel very strongly that we do make choices and that these choices influence the future. 


But just because we feel something is true, does not mean it is true.  It may be an illusion.  For instance, move your head forwards and backwards while looking at the dot in the center and the circles will appear to counter-rotate.



But they don’t really.  So it is possible to believe something is true, to sense it is true with great certainty, even when it isn’t.  Perhaps free will is an instance of this.  How does Smullyan resolve this seeming contradiction between the free will we feel we have and the determinism which is logically inescapable?


2. Smullyan connects these ideas of free will / determinism to the ideas of what is you / what is not you.  In fact, much of what we have read and written in the class has assumed the existence of some entity known as “you” apart from that which is “not you”.  But is this a valid distinction?  Suppose that someone pulls a hair from out of the top of your head and replaces it with a plastic hair.  If I asked, “Are you still you?’, you would probably respond, “Of course.”  Even if I pulled out two or three or however many, you would probably respond, “Yes, still me.”  But what if I could surgically remove one of the 100 billion neurons from your brain and replace it with a useless plastic neuron.  Are you still you?  What if I replace two?  Two hundred?  Two thousand?  Two billion?  When do you cease to be you?  Are you still you when your entire brain has been replaced by useless plastic neurons?


3. What if I removed one of your neurons and replaced it with a small electrical transistor that behaved exactly as your neuron would have behaved.  Are you now half-human/half-computer?  What if I replace two neurons in this way?  Two hundred?  Two billion?  All but one?  When do “you” become a computer?  Does this example demonstrate that computers can be conscious in the same way humans can be conscious?


4. What if I told you that when I was replacing your neurons, I wasn’t throwing them out, but was instead freezing them and arranging them as they had been arranged originally in your brain, only now in a new robotic body.  Then, once all have been pulled out and arranged in the tin head of the robotic body, I thaw them all out so that they can begin working again.  When this new brain begins working, is it you?


5. Now suppose I repeated number four, but instead of just rearranging them in one robot body, I make an organic copy of each neuron I’m transferring and build two brains identical to your original brain, each in its own robot body.  When I thaw both brains and they begin functioning, which one is you?  Which one is your consciousness in?


6. Suppose it became possible to make an organic copy of a small portion of the brain of a friend and to replace a similar portion in your own brain with that copy.  How much of such a replacement would it take before you are no longer you?  One cell?  One thousand?  One million?  When do you no longer exist and when does your friend begin to have two copies of themselves in existence?


7. The examples above may be technically impossible.  But there are actual cases of something very similar, split-brain patients.  If the two halves of your brain were divided, which one would “you” be in, the left or right?  Both?  Neither?


8. What do the answers to questions two through seven indicate about the concept of personal identity?