The probability of a randomly picked currently-living person having a Finnish nationality is less than 0.001. I observe myself being a Finn. What, if anything, should I deduce based on this piece of evidence?
The results of any line of anthropic reasoning are critically sensitive to which set of observers one chooses to use as the reference class, and it’s not at all clear how to select a class that maximizes the accuracy of the results. It seems, then, that the usefulness of anthropic reasoning is limited.
That kind of anthropic reasoning is only useful in the context of comparing hypotheses, Bayesian style. Conditional probabilities matter only if they are different given different models.
For most possible models of physics, e.g. X and Y, P(Finn|X) = P(Finn|Y). Thus, that particular piece of info is not very useful for distinguishing models for physics.
OTOH, P(21st century|X) may be >> P(21st century|Y). So anthropic reasoning is useful in that case.
As for the reference class, “people asking these kinds of questions” is probably the best choice. Thus I wouldn’t put any stock in the idea that animals aren’t conscious.
Just think: In a universe that contains a countable infinity of conscious observers (but finite up to any given moment of time), people’s heads would explode as they tried to cope with the not-even-well-defined probability of being born on or before their birth date.
The probability of a randomly picked currently-living person having a Finnish nationality is less than 0.001. I observe myself being a Finn. What, if anything, should I deduce based on this piece of evidence?
The results of any line of anthropic reasoning are critically sensitive to which set of observers one chooses to use as the reference class, and it’s not at all clear how to select a class that maximizes the accuracy of the results. It seems, then, that the usefulness of anthropic reasoning is limited.
That kind of anthropic reasoning is only useful in the context of comparing hypotheses, Bayesian style. Conditional probabilities matter only if they are different given different models.
For most possible models of physics, e.g. X and Y, P(Finn|X) = P(Finn|Y). Thus, that particular piece of info is not very useful for distinguishing models for physics.
OTOH, P(21st century|X) may be >> P(21st century|Y). So anthropic reasoning is useful in that case.
As for the reference class, “people asking these kinds of questions” is probably the best choice. Thus I wouldn’t put any stock in the idea that animals aren’t conscious.
Just think: In a universe that contains a countable infinity of conscious observers (but finite up to any given moment of time), people’s heads would explode as they tried to cope with the not-even-well-defined probability of being born on or before their birth date.