This is a continuation of this in which I wrote,

If (as I advocate) you believe that what matters about you is not your subjective experiences but rather what effects you have on objective reality, the questions become easy to answer.

Let me give an example. Suppose you are woken up tomorrow morning by someone who seems to be an exact copy of you. What to do? If what matters is effects on objective reality, then the salient effects of that development are two. One is that now you have twice the capacity to affect reality. Or if you object to bending the word "you" to include two people, now there are two people implementing your plans rather than one. The second salient effect is that there is another mouth to feed (and to cloth and to entertain and -- if the mouth is a young mouth -- to educate). I wrote,

they lead to questions such as whether a subjective experience experienced after he has been frozen and revived has the same importance or undeniable impact as an experience he might have yesterday or tomorrow.

Perhaps it will prove illuminating to consider what a definitive answer to that question would look like.

Suppose the next issue of the journal Nature reports a blockbuster discovery of something similar to a bank account or an accumulator that is incremented every time you have a pleasurable experience and decremented every time you have a painful experience. Since this accumulator is part of objective reality, we can now (if we are good enough at science) use the methods of physics, biology, etc, to predict the effects a freezing and revival will have an the accumulator(s). (Perhaps there are 2 accumulators now.) That is what a definitive answer would look like.

But surely no one believes that physicists, biologists or neuroscientists will find anything like this bank account or accumulator. But I think comparing that hypothetical definitive answer with the best nonhypothetical answers you can find is a good test of those nonhypothetical answers.

changed March 4, 2008