"Scientists sometimes (as is well known) continue to work with a theory which they themselves know is false. Laymen, when they hear of such a case, are apt to be audibly critical of the scientists' conduct; but of course they have no better theory to suggest, and the only result is, that the scientists grow angry and impatient with their lay critics. But these features of scientists' behaviour are not ones which deserve esteem, and still less, imitation. They are departures from rational behavior, not forms of it. They arise only because professional scientists, without the guidance of some theory, however unsatisfactory, do not know what to do with themselves."
(Who said this?)
(Who said this?)