retro spective Edit

An underlying premise is the multi-verse theory: out of billions of possible universes we were the one that happened to be in existence, but the sample space is actually two: Either we exist or we don't.

Black Mischief p.294 Berlinski: I have spoken of a specific protein. If any protein will do, the odds improve. In a uniform probability space , it is certain that one among the possible events will occur. The British biologist Peter Medawar has seized upon this point...and went in the wrong direction with it.

<quoting medaware> In the games of whist or bridge any one particular hand is just as unlikely to turn up as any other. If I pick up and inspect a certain hand and then declare myself utterly amazed that such a hand should have been dealt to me , considering the odds against it, I should be told by those who have steeped themselves in mathmatical reasoning that its prob. cannot be measured retrospectively, but only against a prior expectation. For much the same reason it seems to me profitless to speak of natural selection's 'generating improbability" is silly to be thunderstruck by the evolution of organ A if we should have been just as thunderstruck by a turn of events that had led to the evolution of B or C instead. <End quoting medaware>

Berlinski says: "... Medawar is roughly right about probability. The fallacy he refers to is retrospective specification and consists precisely in reading back into an original sample space information revealed only on the realization of the actual event. In poker , a deal distributes n hands of equal probability: 1 in 2598160 as it happens. This sample space is specified retrospectively if one hand in particular is contrasted with 2598159 hands that remain; and probabilities assigned to the partition so created. What appears initially as one among equiprobable events becomes under RS an improbable event in a sample space of only two points. It is embarrassing for an author to point out such things...."

Notes Edit

Links Edit 22min fallacy of retrospective determination and violation of law of excluded middle

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