# Help me understand Earman and Salmon's pragmatic vindication

"Hume showed convincingly that, if nature is uniform, inductive reasoning will work very well, whereas, if nature is not uniform, inductive reasoning will fail. This much is pretty easy to see. [Some philosophers have] suggested, however, that we should consider other options besides the use of induction for purposes of trying to predict the future. Suppose we try consulting a crystal gaze to get our predictions. We cannot say [in advance] that we will get correct predictions, even if nature turns out to be uniform, but we cannot say [in advance] that we won’t. We just don’t know... What if nature is not uniform and we do not use induction? One possibility is simply not to make any predictions at all; whether nature is uniform or not, that obviously does not result in successful predictions. Another possibility is that we adopt a noninductive method such as crystal gazing. Any method – including wild guessing – may yield a true prediction once in a while by chance, whether nature is uniform or not. But suppose that crystal gazing were to work consistently. Then, that would be an important uniformity, and it could be established inductively – that is, on the basis of the observed record of the crystal gazer in making successful predictions we could infer inductively that crystal gazing will be successful in making correct predictions in the future. Thus, if crystal gazing can produce consistent successful predictions so can the use of induction. What has just been said about crystal gazing obviously applies to any noninductive method. [Some philosophers have] therefore concluded that if any method will succeed consistently, then induction will succeed consistently. The same conclusion can be reformulated (by contraposition) as follows: If induction does not work, then no other method will work. We therefore have everything to gain and nothing to lose – so far as predicting the future is concerned – by adopting the inductive method. No other method can make an analogous claim."

I really don't seem to understand the crystal gaze example. Can someone please help me? I know I should elaborate and try to explain what I think I understood but my thoughts are too confused for that and I would need some guidance.

• It is a "typical" philosophical argument, based on some sort of "mental experiment" trying to prove something thta is quite impossible to prove. Uniformity of nature is an assumption probbaly built-in into our (animal) harware and software. Thus, inductive reasoning very often succeed. If we can test "crystal gazing" foundi g a good percentage od predictive success, this can be perfectly compatible with non-uniformity of nature: crystal gaze can predict the result of soccer plays: this does not implies that we can use induction to predict them. Mar 23, 2018 at 9:24