94 PART II. -SOME IMPORTANT METHODOLOGICAL TERMS. 



men is therefore as mythical a belief as that animals came 

 suddenly into being. 1 



In pure theory no reason exists why some thinker should 

 not have guessed a world formula which should irresistibly 

 reveal to us the whole mechanism and organism of nature; but 

 in practice, we have seen, the larger generalisations of any 

 value have grown out of smaller ones, and where relevant 

 knowledge did not abound, the hypotheses framed, even if true, 

 could not be verified. If the youthful Newton had observed 

 an apple fall from a tree, and had straightway committed to 

 paper his system of the worlds, Mill's view. might be upheld; 

 but the perusal of Newton's Principia, with its profuse allusions 

 to other authors, should convince anyone that the apple theory 

 is without justification. When, then, we study the actual facts 

 concerning Newton's theory, say in Sir David Brewster's Life 

 of Newton, we are not surprised to learn that many scholars 

 were responsible for the different portions of the solution and 

 that the solution slowly grew, and continued growing after 

 Newton, as the result of mountains of collective labour. We 

 should even experience some difficulty in deciding what vital 

 portion of the general gravitation hypothesis was ascribable to 

 Newton himself, considering that the conception of the unity 

 of the solar system, the revolution of the earth round its axis 

 and round the sun, the discovery of the concept of gravity 

 and its extension to the solar system, the quantitative determi- 

 nation of the velocities and the accelerations of falling bodies, 

 and even the law of inverse squares, were not apparently 

 discovered by the author of the Principia.' 2 



Darwin freely adopted suggestions from others: 



"The starting points of many of Darwin's researches were furnished 

 him by other intelligent men." (Frank Cramer, op. cit., p. 47.) "After his 

 return from the Beagle voyage, Mr. Wedgwood of Maer Hall suggested to 

 him that the apparent sinking of superficial bodies, ashes, marl, cinders, etc.. 

 in the earth is due to the action of earthworms." (Ibid., p. 48.) "Boitard 

 and Corbie merely made the observation that, when they crossed certain 

 breeds of pigeons, birds coloured like the Columba livia, or common dove- 



1 Ernest Naville in his La logique de I'hypothese, recognises that hypo- 

 theses should not be accepted till after verification; but, starting with the 

 assumption that hypotheses are the product of genius, he is content to urge 

 his view passionately without examining the evidence. 



Welton seems to waver between opposed explanations of hypotheses: 

 "Facility in framing hypotheses cannot be reduced to rule, and hence falls 

 outside the province of logic." (Manual of Logic, vol. 2, p. 86.) "In most 

 cases the attempts of previous enquirers have shown more or less plainly 

 in what direction explanation must be sought: either by the partial estab- 

 lishment of some hypothesis, or by making manifest the inadmissibility 

 of others." (Ibid., vol. 2, p. 86.) 



2 On the same principles Jenner proves to be an enthusiastic summariser 

 and not a discoverer, and this is partly or wholly true of perhaps most 

 men of highest repute. Strange as it may seem, the "great" scientist or artist 

 only appears when the work of invention or discovery has been virtually 

 completed. 



