...as in that rule of arithmetic,... regula falsi,... so in physiology it is sometimes conducive to the discovery of truth, to permit the understanding to make an hypothesis....
[By] examining how far... that hypothesis [goes], the understanding may, even by its own errors, be instructed. For it has truly been observed by a great philosopher [Bacon], that truth does more easily emerge from error than confusion.
Boyle 1661... the worth of a hypothesis lies mainly in that by a manner of regula falsi it leads us always nearer to the truth.
Mach, 1863
... The process of scientific discovery is cautious and rigorous, not by abstaining from hypotheses but by rigorously comparing hypotheses with facts, and by resolutely rejecting all which the comparison does not confirm.
William Whewell, 1858
... the way to get at the merits of a case is not to listen to the fool who imagines himself impartial, but to get it argued with reckless bias for and against. To understand a saint you must hear the devil’s advocate....
Shaw, 1907
There is a saying that was attributed to Louis Agassiz (no relation of mine) to the effect that every new idea is first declared contrary to reason, and then contrary to religion, and when it overcomes these two obstacles it is declared to be old hat. Popper’s philosophy is just now passing from the second to the third stage - the stage of being old hat. Be that as it may, allow me to record, as an observation, that a number of distinguished philosophers, particularly of science, now seem to be preparing the grounds for this transition: they are playing amongst themselves a game
Note. The mottos are from Robert Boyle, Certain Physiological Essays (1661) Proemial Essay; E. Mach, in Oesterreichische Zeitschriftfurpraktischen Heilkunde 9 (1863), 366;
W. Whewell, Novum Organum Renovatum, 1858, Of Certain Characteristics of Scientific Induction, Aphorism IV; G. B. Shaw, Preface to his The Sanity of Art (1907). that I both witnessed and heard reported in private conversations any number of times - the game of showing that every new idea that you can quote from Popper has been previously published by others. Various writings of various thinkers, whether scientists or philosophers, of the last three centuries, avail themselves of this game.
It is not hard to find in them passages with striking resemblance to important remarks of Popper. His refutability criterion for the scientific character of theories, which is perhaps the best known idea of his, can be found in previous writings in one version or another. Even what I consider his most important idea, his idea that scientific theories are series or stages of approximations to the truth, is not new. I have found expressions of it in the works of Priestley in the eighteenth century, Laplace in the early nineteenth century, Ludwig Boltzmann at the turn of the century, in an appendix to Duhem’s Aim and Structure of Physical Theory, and even in rather obscure and almost entirely unknown passages, in a few books, and in an article by Bertrand Russell where he contrasts Newton’s theory with Einstein’s.1 The American philosopher Max Otto, in a discussion of scientific method, quotes a remark made by a working geologist, Lewis G. Westgate, incidentally to a geological discussion; in this quotation Popper’s whole philosophy of science may be declared to be stated in capsule form.2 So I think the game of finding quotations from writers previous to Popper is not difficult to play, and the results are largely successful. I would even go further and say that many of the remarkably striking technical ideas of Popper’s - his ideas of simplicity, of degrees of testability, and other technical ideas - may be found in embryo form in works of earlier writers, particularly William Whewell and Charles Saunders Peirce. Peirce was an unsystematic philosopher, perhaps, but also brilliant and versatile. Perhaps Popper is the exact opposite of Peirce, because the most characteristic thing about him is the systematic and logical way he presents his ideas and fully works them out. But I am anticipating myself.I.