One may rationally stick to a degenerating research programme until it is overtaken by a rival and even after. What one must not do is to deny its poor public record... It is perfectly rational to play a risky game: what is irrational is to deceive oneself about the risk.
Imre Lakatos, John Worrall, Gregory Currie (1980). “The Methodology of Scientific Research Programmes: Volume 1: Philosophical Papers”, p.117, Cambridge University Press
