Richard Swinburne on Probabilities and the Anthropic Principle
Suppose that a madman kidnaps a victim and shuts him in a room with a card-shuffling machine. The machine shuffles ten decks of cards simultaneously and then draws a card from each deck and exhibits simultaneously the ten cards. The kidnapper tells the victim that he will shortly set the machine to work and it will exhibit its first draw, but that unless the draw consists of an ace of hearts from each deck, the machine will simultaneously set off an explosion which will kill the victim, in consequence of which he will not see which cards the machine drew. The machine is then set to work, and to the amazement and relief of the victim the machine exhibits an ace of hearts drawn from each deck. The victim thinks that this extraordinary fact needs an explanation in terms of the machine having been rigged in some way. But the kidnapper, who now reappears, casts doubt on this suggestion. 'It is hardly surprising', he says, 'that the machine draws only aces of hearts. You could not possibly see anything else. For you would not be here to see anything at all, if any other cards had been drawn.'LinkWhat needs to be understood is that the odds for any ten cards drawn by this machine were exactly the same, 1 in 145 sextillion I'm told. That is, the odds that this machine would have instead drawn ten Queen of Spades were exactly the same as drawing ten Aces of Hearts, or any other combination of cards. So any ten cards drawn in the order they were drawn were equally, well, impossible. Who would bet much money on predicting which cards were drawn in what order, right?
In this case the cards saved a person's life. This expresses the anthropic principle in that if those particular cards had not been drawn that victim could not possibly be alive to see them just as if our universe turned out differently we as human beings could not be here to see it either. Okay so far?
Here then is Swinburne's conclusion:
The fact that this peculiar order is a necessary condition of the draw being perceived at all makes what is perceived no less extraordinary and in need of explanation. The teleologist's starting-point is not that we perceive order rather than disorder, but that order rather than disorder is there. Maybe only if order is there can we know what is there, but that makes what is there no less extraordinary and in need of explanation.But if we return to Swinburne's analogy let's instead kidnap 1 in 145 sextillion life forms and match them up with 1 in 145 sextillion combinations of cards such that for every set of ten cards drawn the corresponding life form will live to see it. So it would hardly be surprising that if any given set of cards are drawn then the corresponding life form sees them. That's what Swinburne fails to understand.
Let me put this in a better context since I know the odds that our universe would produce life forms in every scenario is impossible. So here it is: If the odds are 1 in 145 sextillion that the universe turned out differently then the odds are 1 in 145 sextillion that the universe turned out differently. And that's all there is to his logic! So it's a tautology, true by definition. The fact that it did turn out the way it did such that we see the universe is not surprising since if it had turned out differently we wouldn't be here to observe it. The fundamental flaw in his line of reasoning is that there are other life forms that would exist if it had turned out differently, although what they might look like we don't have much of a clue. If, for instance, nine Aces of Hearts were drawn by this machine and one King of Hearts then the life form that represents those drawn cards would be able to see it, and so forth and so on.
Cheers.
HT: BK