 Gold began by considering a reformulation of the standard philosophical problem of induction. The trouble with the question ‘Which hypothesis is correct given the totality of the data?’ is of course the one that Hume saw: if the domain is unbounded, no finite amount of data can answer the question. Any finite body of evidence will be consistent with arbitrarily many hypotheses that are not consistent with each other. But Gold proposed replacing the question with a very different one: Which tentative hypothesis is the one to pick, given the data provided so far, assuming a finite number of wrong guesses can be forgiven?