February 7, 1890.] 



SCIENCE. 



93 



tion. For a time it is likely to be held in a tentative way 

 with a measure of candor. With this tentative spirit and 

 measurable candor, the mind satisfies its moral sense, and 

 deceives itself with the thought that it is proceeding cautiously 

 and impartially toward the goal of ultimate truth. It fails to 

 recognize that no amount of provisional holding of a theory, 

 so long as the view is limited and the investigation partial, 

 justifies an ultimate conviction. It is not the slowness with 

 which conclusions are arrived at that should give satisfaction 

 to the moral sense, but the thoroughness, the completeness, the 

 all-sidedness, the impartiality, of the investigation. 



It is in this tentative stage that the affections enter vrith 

 their blinding influence. Love was long since represented as 

 blind, and what is true in the personal realm is measurably 

 true in the intellectual realm. Important as the intellectual 

 affections are as stimuli and as rewards, they are nevertheless 

 dangerous factors, which menace the integrity of the intellec- 

 tual processes. The moment one has offered an original expla- 

 nation for a phenomenon which seems satisfactory, that 

 moment affection for his intellectual child springs into exist- 

 •ence; and as the explanation grows into a definite theory, his 

 parental affections cluster about his intellectual offspring, and 

 it grows more and more dear to him, so that, while he holds it 

 seemingly tentative, it is still lovingly tentative, and not 

 impartially tentative. So soon as this parental affection takes 

 possession of the mind, there is a rapid passage to the adoption 

 of the theory. There is an unconscious selection and magnify- 

 ing of phenomena that fall into harmony with the theory and 

 support it, and an unconscious neglect of those that fail of 

 coincidence. The mind lingers with pleasure upon the facts 

 that fall happily into the embrace of the theory, and feels a 

 natural coldness toward those that seem refractory. Instinc- 

 tively there is a special searching-out of phenomena that sup- 

 port it, for the mind is led by its desires. There springs up, 

 also, an unconscious pressing of the theory to make it fit the 

 facts, and a pressing of the facts to make them fit the theory. 

 When these biasing tendencies set in, the mind rapidly degen- 

 erates into the partiality of paternalism. The search for facts, 

 the observation of phenomena and their interpretation, are all 

 dominated by affection for the favored theory until it appears 

 to its author or its advocate to have been overwhelmingly estab- 

 lished. The theory then rapidly rises to the ruling position, 

 and investgaton. observation, and interpretatioti are controlled 

 and directed by it. From an unduly favored child, it readily 

 becomes master, and leads its author whithersoever it will. The 

 subsequent history of that mind in respect to that theme is but 

 the progressive dominance of a ruling idea. 



Briefly summed up, the evolution is this : a premature expla- 

 nation passes into a tentative theory, then into an adopted 

 theory, and then into a ruling theory. 



When the last stage has been reached, unless the theory 

 happens, perchance, to be the true one, all hope of the best 

 results is gone. To be sure, truth may be brought forth by an 

 investigator dominated by a false ruling idea. His very errors 

 may indeed stimulate investigation on the part of others. But 

 the condition is an unfortunate one. Dust and chaff are 

 mingled with the grain in what should be a winnowing process. 



As previously implied, the method of the ruling theory 

 ■occupied a chief place during the infancy of investigation. It 

 is an expression of the natural infantile tendencies of the mind, 

 though in this case applied to its higher activities, for in the earlier 

 stages of development the feelings are relatively greater than 

 in later stages. 



Unfortunately it did not wholly pass away with the infancy 

 of investigation, but has lingered along in individual instances 

 to the present day, and finds illustration in universally learned 

 men and pseudo-scientists of our time. 



The defects of the method are obvious, and its errors great. 

 If I were to name the central psychological fault, I should say 

 that it was the admission of intellectual affection to the place 

 that should be dominated by impartial intellectual rectitude. 



So long as intellectual interest dealt chiefly with the intan- 

 gible, so long it was possible for this habit of thought to 



survive, and to maintain its dominance, because the phenomena 

 themselves, being largely subjective, were plastic in the hands 

 of the ruling idea; but so soon as investigation turned itself 

 earnestly to an inquiry into natural phenomena, whose mani- 

 festations are tangible, whose properties are rigid, whose laws 

 are rigorous, the defects of the method became manifest, and 

 an effort at reformation ensued. The first great endeavor 

 was repressive. The advocates of reform insisted that 

 theorizing should be restrained, and efforts directed to 

 the simple determination of facts. Tlie effort was to 

 make scientific study factitious instead of causal. Be- 

 cause theorizing in naiTOw lines had led to manifest evils, 

 theorizing was to be condemned. The reformation urged was 

 not the proper control and utilization of theoretical effort, but 

 its suppression. We do not need to go backward more than 

 twenty years to find ourselves in the midst of this attempted 

 reformation. Its weakness lay in its narrowness and its 

 restrictiveness. There is no nobler aspiration of the human 

 intellect than desire to compass the cause of things. The 

 disposition to find explanations and to develop theories is 

 laudable in itself. It is only its ill use that is reprehensible. 

 The vitality of study quickly disappears when the object sought 

 is a mere collocation of dead unmeaning facts. 



The inefficiency of this simply repressive reformation becom- 

 ing apparent, improvement was sought in the method of the 

 working hypothesis. This is affirmed to be the scientific 

 method of the day, but to this I take exception. The working 

 hypothesis differs from the ruling theory in that it is used as a 

 means of determining facts, and has for its chief function the 

 suggestion of lines of inquiry ; the inquiry being made, not for 

 the sake of the hypothesis, but for the sake of facts. Under 

 the method of the ruling theory, the stimulus was directed to 

 the finding of facts for the support of the theory. Under the 

 working hypothesis, the facts are sought for the purpose of 

 ultimate induction and demonstration, the hypothesis being but 

 a means for the more ready development of facts and of their 

 relations, and the arrangement and preservation of material for 

 the final induction. 



It will be observed that the distinction is not a sharp one, and 

 that a working hypothesis may with the utmost ease degenerate 

 into a ruling theory. Affection may as easily cling about an 

 hypothesis as about a theory, and the demonstration of the one 

 may become a ruling passion as much as of the other. 



Conscientiously followed, the method of the working hypoth- 

 esis is a marked improvement upon the method of the ruling 

 theory; but it has its defects, — defects which are perhaps best 

 expressed by the ease with which the hypothesis becomes a 

 controlling idea. To guard against this, the method of mul- 

 tiple working hypotheses is urged. It differs from the former 

 method in the multiple character of its genetic conceptions and 

 of its tentative interpretations. It is directed against the 

 radical defect of the two other methods; namely, the partiality 

 of intellectual parentage. The effort is to bring up into view 

 every rational explanation of new phenomena, and to devleop 

 every tenable hypothesis respecting their cause and history. 

 The investigator thus becomes the parent of a family of hypoth- 

 eses; aid, by his parental relation to all, he is forbidden to 

 fasten his affections unduly upon any one. In the nature of 

 the case, the danger that springs from affection is counteracted, 

 and therein is a radical difference between this method and the 

 two preceding. The investigator at the outset puts himself in 

 cordial sympathy and in parental relations (of adoption, if not 

 of authorship) with every hypothesis that is at all applicable to 

 the case under investigation. Having thus neutralized the 

 partialities of his emotional nature, he proceeds with a certain 

 natural and enforced erectness of mental attitude to the in- 

 vestigation, knowing well that some of his intellectual children 

 will die before maturity, yet feeling that several of them may 

 survive the results of final ivestigation, since it is often the 

 outcome of inquiry that several causes are found to be involved 

 instead of a single one. In following a single hypothesis, the 

 mind is presumably led to a single explanatory conception. 

 But an adequate explanation often involves the co-ordination of 



