Karl Popper
Can it be shown wrong
A theory that explains everything explains nothing
Conjectures and Refutations
Astrology explains events and so does physics. This page is about the line Popper drew between them.
What actually happened?
As a teenager in Vienna he was reading Einstein alongside the theories then in fashion, whose followers could account for any case at all and treated that as proof of strength. General relativity did the opposite. It predicted that starlight passing the sun would bend by a specific amount, and a different measurement would have finished it. The 1919 eclipse matched. A theory which is not refutable by any conceivable event is non-scientific, he concluded, and irrefutability is a vice rather than a virtue. The difference was never explanatory power.
Ask what would refute it, not what supports it
Facing any claim, the useful question is not what evidence there is but what observation would make you drop it. If nothing would, the claim carries no testable content, and being internally consistent does not make up for that.
Market sentiment drove the rise. And the fall? Also sentiment. It covers every outcome, which is exactly why it tells you nothing.
The refuting condition has to be written down first
People are extremely good at reading any result as support. The only reliable antidote is to nail the criterion in place before the result arrives. Setting the standard afterwards leaves you a position that cannot lose, which is the same as one that cannot inform.
Before launch, write down that if this number has not moved in two weeks the assumption was wrong. In advance, so there is nothing left to renegotiate.
Being refuted is not the same as being discarded
The common misreading is that a falsified theory goes in the bin. His demand is that a theory be exposed to serious attempts to break it, and good ones usually come out stronger. What matters is whether you genuinely tried.
Every quarter, go hunting for the strongest case against your central judgement. If you look hard and find nothing, that is when it is worth trusting.
How do I use it today?
Where you are: somebody has handed you a claim that sounds thoroughly reasonable.
Ask first: under what circumstances would this be false, and can they answer that at all?
Where it goes wrong: using the criterion to dismiss every field that cannot be measured, or as a debating move that leaves nobody able to conclude anything.
Lines to keep
Irrefutability is not a virtue of a theory but a vice.
Say in advance what would make you admit you were wrong.
Same situation, other people are asking
By the time the data is in, will it be too late?Everyone I know is in this. I don't actually understand it.I keep listing reasons this will work. Should I do the other list?Everything I know about this came up one reporting line.I don't have enough information · all 12 questions →If this one named what you are going through,
send it to someone who needs it, or keep it somewhere you will find it again.