The kind of knowledge which is supported only by observations and is not yet proved must be carefully distinguished from the truth; it is gained by induction, as we usually say. Yet we have seen cases in which mere induction led to error.

— Leonhard Euler, Specimen de usu observationum in mathesi pura

From Opera Omnia, series 1, vol. 2; also quoted by George Pólya in Induction and Analogy in Mathematics (1954).

Topics: mathematics