The great difference between induction and hypothesis is that the former infers the existence of phenomena such as we have observed in cases which are similar, while hypothesis supposes something of a different kind from what we have directly observed, and frequently something which it would be impossible for us to observe directly.

Chance, Love and Logic: Philosophical Essays, Deduction, Induction, Hypothesis (p. 149), Harcourt, Brace & Company, Inc. 1923