SECTION 12. HYPOTHESES. 89 



SECTION XII. HYPOTHESES. 



35. Consistently with the different views Bacon and Mill 

 adopt concerning the method to be employed in investigating 

 data, they disagree in the value to be assigned to hypotheses, 

 for whereas the former denounced hypotheses not based on 

 an extensive and diversified examination of facts, the latter 

 considered spontaneously arisen hypotheses the main instrument 

 of scientific advance. Jevons and most later logicians agree 

 with Mill, though it is strange that no determined effort should 

 have been made by these logicians to ascertain exactly and 

 in detail the process of arriving at a hypothesis. We know 

 how vigorously Newton denounced recourse to conjectures not 

 suggested by a responsible study of facts, and yet, by a per- 

 verse fate, the idlest of idle legends is eternally reiterated 

 to the effect that Newton derived his conception of the law 

 of gravitation from perceiving an apple fall while a youth. 

 Hypotheses are not only figured to-day by many logicians as 

 the sine qua non of science : they are looked upon as offering 

 almost the sole device for extending truth. In vain have 

 scholars like Herschel protested that "the liberty of specula- 

 tion which we possess in the domains of theory is not like 

 the wild licence of the slave broke loose from his fetters, but 

 rather like that of the freeman who has learned the lessons 

 of self-restraint in the school of just subordination". (Discourse, 

 [201.].) The protests have roused no echo, and the solid ob- 

 servational activities of the man of science have been placidly 

 ignored. 



What is a hypothesis? 1 We may define it as a plausible con- 

 jecture suggested by a careful preliminary examination, for which 



1 "An hypothesis is any supposition which we make (either without 

 actual evidence, or on evidence avowedly insufficient) in order to endea- 

 vour to deduce from it conclusions in accordance with facts which are 

 known to be real ; under the idea that if the conclusions to which the 

 hypothesis leads are known truths, the hypothesis itself either must be, 

 or at least is likely to be, true." (Mill, Logic, bk. 3, ch. 14, 4.) 



"Hypothesen im wissenschaftlichen Sinne sind weder Tatsachen noch 

 \villkiirliche und unbegriindete Annahmen, sondern Voraussetzungen, die 

 um der Tatsachen willen gemacht werden, aber'selbst der tatsa'chlichen 

 Nachweisung sich entziehen." . (Wundt, Logik, vol. 1, p. 439. ) 



"Die Hypothese ist die voiliiufige Annahme der Wahrheit einer un- 

 i^ewissen Framisse, die auf eine dafiir gehaltene Ursache geht, zum Zweck 

 ihrer Priifung an ihren Consequenzen." (Uberweg, System der Logik, 

 p. 394.) "Wissenschaftliche Hypothesen sind nicht (wie Apelt, Theorie der 

 Induct., sich ausdriickt) 'aus der Luft gegriffene Behauptungen', sondern 

 als Resultate zulassiger Riickschliisse aus Erfahrungen und zugleich als 

 PrMmissen versuchsweiser Deductionen die notwendigen Vorstut'en der 

 adaquaten Erkenntniss." (Ibid., p. 386.) 



"It [hypothesis] means the suppositions, suggestions, or guesses, as to 

 any matter unknown, leading to experimental or other operations, for proof 

 or disproof." (Bain, Logic, vol. 2, p. 128.) "Many hypotheses are of the. 

 nature of analogies or comparisons." (Ibid., p. 147.) 



