xxvi.] CHARACTER OF THE EXPERIMENTALIST. 577 



truth. It is difficult to imagine a less likely way of arriv- 

 ing at great discoveries. The greater the array of facts, 

 the less is the probability that they will by any routine 

 system of classification disclose the laws of nature they 

 embody. Exhaustive classification in all possible orders is 

 out of the question, because the possible orders are practi- 

 cally infinite in number. 



It is before the glance of the philosophic mind that 

 facts must display their meaning, and fall into logical order. 

 The natural philosopher must therefore have, in the first 

 place, a mind of impressionable character, which is affected 

 by the slightest exceptional phenomenon. His associating 

 and identifying powers must be great, that is, a strange fact 

 must suggest to his mind whatever of like nature has pre- 

 viously come within his experience. His imagination must 

 be active, and bring before his mind multitudes of relations 

 in which the unexplained facts may possibly stand with 

 regard to each other, or to more common facts. Sure and 

 vigorous powers of deductive reasoning must then come into 

 play, and enable him to infer what will happen under each 

 supposed condition. Lastly, and above all, there must be 

 the love of certainty leading him diligently and with per- 

 fect candour, to compare his speculations with the test of 

 fact and experiment. 



Freedom of Theorising. 



It would be an error to suppose that the great discoverer 

 seizes at once upon the truth, or has any unerring method 

 of divining it. In all probability the errors of the great 

 mind exceed in number those of the less vigorous one. 

 Fertility of imagination and abundance of guesses at truth 

 are among the first requisites of discovery; but the erroneous 

 guesses must be many times as numerous as those which 

 prove well founded. The weakest analogies, the most 

 whimsical notions, the most apparently absurd theories, 

 may pass through the teeming brain, and no record remain 

 of more than the hundredth part. There is nothing really 

 absurd except that which proves contrary to logic and ex- 

 perience. The truest theories involve suppositions which 

 are inconceivable, and no limit can really be placed to the 

 freedom of hypothesis. 



P P 



