Who ever heard a theologian preface his creed, or a politician conclude his speech with an estimate of the probable error of his opinion?
Bertrand RussellScientific method, although in its more refined forms it may seem complicated, is in essence remarkably simply. It consists in observing such facts as will enable the observer to discover general laws governing facts of the kind in question. The two stages, first of observation, and second of inference to a law, are both essential, and each is susceptible of almost indefinite refinement. (1931)
Bertrand Russell