It's kind of like how the modern standards of mathematical "proof" don't extend backwards very well. Nobody would say that Euler wasn't one of the greatest math

It's kind of like how the modern standards of mathematical "proof" don't extend backwards very well. Nobody would say that Euler wasn't one of the greatest mathematicians of all time, but much of his work was very unrigorous despite being accepted by the math community long before it was formally verified. Similarly there is lots of science that was settled way before it actually made falsifiable predictions which were confirmed through experiment. The classic example is Newtonian physics, which was contradicted by several observations that were only reconciled by Einstein. Another example would be like Boyle's models of gas and liquid. These models all hold approximately, and are very useful (hence their acceptance), but wouldn't really pass the criterion of falsifiability. Kuhn frames it as "anything goes", which is supposed to be what the horrified scientist utters to themself as they peruse the historical record of their field. Scientists tend to go with "whatever works best" (and whatever secures more funding), rather than following a strictly falsificationist paradigm. More and better context here: https://www.nature.com/nature-index/news/the-idea-that-a-scientific-theory-can-be-falsified-is-a-myth https://www.nature.com/nature-index/news/the-idea-that-a-sci...