SCIENTIFIC METHOD 53 



frontiers of reason that are likely to work with any profit 

 here.' 



In this forcible and eloquent way Tyndall introduces 

 his subject ; but let me impress upon you that although 

 the imaginative aspect becomes conspicuous in the 

 scientific conceptions of specially gifted men, it is in 

 reality an essential feature of all scientific research. 

 Its scope may be limited, as in ascertaining the more 

 immediate relationships of some restricted group of 

 natural phenomena, but since this involves passing from 

 the known to the unknown, even though the passage is 

 a step, the imaginative gift which enables the passage to 

 be made is essential. 



When, however, the passage from the known to the 

 unknown is of a character which far transcends present 

 or even possible experience, then the daring nature of 

 the flight, impressing in its turn the imagination of 

 mankind, exacts homage for the creative power thus 

 revealed. 



I select, in order to illustrate this aspect of the scientific 

 method, one or two of those scientific conceptions (law, 

 hypothesis and theory) which have changed the thought 

 of mankind. 



Newton's enunciation of the law of gravitation is so 

 familiar that I might merely mention it, but I desire to 

 do more than this, because I do not find myself in com- 

 plete accord with the view already put before you by my 

 colleague, Professor Case, who has selected this as a 

 typical example of logical deduction. For my own part I 

 regard Newton's statement that every particle of matter 

 in the universe exercises an attractive force on every 

 other particle which varies inversely as the square of the 

 distance between them, as an induction, the conception 

 of a creative mind gifted with imagination. Professor 



