90 PART II. SOME IMPORTANT METHODOLOGICAL TERMS. 



the completest proof obtainable is being sought in order to 

 convert it into a fact or established theory. Should an asser- 

 tion be self-evident, as Euclid's eighth axiom that things which 

 are equal to the same thing are equal to one another, we 

 conceive it as independent of, and as requiring no, proof. On 

 the other hand, if an assertion is patently incredible, as that 

 air is impenetrable by human beings, we dismiss it without 

 striving to prove or disprove it. Nor can we speak of a hypo- 

 thesis which is incapable of direct and indirect proof, for, by 

 the definition, partial proof alone entitles a conjecture to be 

 raised to the dignity of a hypothesis. A hypothesis, then, 

 asserts something which is neither self- evidently true nor self- 

 evidently false, nor incapable of some kind of proof, as when 

 it is, wrongly, asserted that the cortical substance of the rice 



"Hypothesis is a name that may be applied to any conception by 

 which the mind establishes relations between data of testimony, of per- 

 ception, or of sense, so long as that conception is one among alternative 

 possibilities, and is not referred to reality as a fact." (Bosanquet, Logic, 

 vol. 2, p. 155.) "A hypothesis is a hypothesis because it is not, to begin 

 with, present in the data, and has to be brought there by mediation." 

 (Ibid., pp. 169-170.) 



"The strength of a hypothesis lies in its power of co-ordinating ob- 

 served facts and of forecasting intelligently the discoveries of the future." 

 (Whetham, The Recent Development of Physical Science, p. 230.) 



"Different suggestions present themselves with varying degrees of 

 plausibility. Some are passed by as soon as they arise. Others gain a 

 temporary recognition. Some are explicitly tested with resulting accep- 

 tance or rejection. The acceptance of any one explanation involves the 

 rejection of some other explanation. During the process of verification 

 or test the newly advanced supposition is recognised to be more or less 

 doubtful. Besides the hypothesis which is tentatively applied there is 

 recognised the possibility of others." (M. L. Ashley, "The Nature of Hypo- 

 thesis", in J. Dewey's Studies in Logical Theory, 1903, p. 155.) "The 

 predicate arises in case of failure of some line of activity going on in 

 terms of an established habit." (Ibid., p. 170.) "It is pointed out by 

 Welton that the various ways in which hypotheses are suggested may 

 be reduced to three classes, viz., enumerative induction, conversion of 

 propositions, and analogy." (Ibid., p. 171.) 



"Aucune regie, aucun principe ne pent guider le savant dans 1'art de 

 construire des hypotheses ayant une valeur heuristique: qu'elles ne con- 

 tredisent a aucune loi precedemment etablie, qu'elles soient abandonnees 

 sans retard des qu'elles recoivent le moindre dementi de 1'experience, 

 c'est tout ce que 1'on peut exiger d'elles. Et, encore, que d'hypotheses 

 contraires a certaines lois qu'on croyait certaines, en contradiction avec 

 certains faits qu'on croyait expliques, ont cependant triomphe, demontrant 

 la faussete de ces pretendues lois auxquelles elles contredisaient, la fausse 

 explication des faits qu'on leur opposait. En somme, done, 1'hypothese 

 est affaire d'intuition; c'est le secret du savant, de 1'homme de genie." 

 (Paul Caullet, Elements de sociologie, 1913, p. 67.) 



"Before we go further, however, we must be clear as to one general 

 truth. We must understand that the invention of hypotheses is the work 

 of the scientific genius." (S. H. Mellone, An Introductory Text-Book of 

 Logic, 1895, p. 332.) This appears to be also the view of Louis Couturat. 

 in his Les principes des mathematiques, 1905. 



"The value of an hypothesis depends upon its usefulness and expe- 

 diency, and on its power of indicating the lines of future inquiry." 

 (E. Thorpe, History of Chemistry, vol. 2, p. 95.) 



