^resident's address. -ll 



affect the reputation of one unit of creation or involve the whole life 

 of a nation, and according to the greatness of the issue we shall honour 

 the man who, having taken the risk, succeeds. But whether the scale 

 be microscopic or interstellar, the essence of the faculty of blending 

 theory and practice is the same, and both men of books and men of 

 action are to be found in the philosopher's study and the laboratoiy, 

 as well as in the workshop or on the battlefield. Modern science 

 began, not at the date of this or that discovery, but on the day when 

 Galileo decided t-o publish his Dialogues m the language of his nation. 

 This was a deliberate act destined to change the whole aspect of science, 

 which, ceasing to be the occupation of a privileged class, became the 

 property of the community. Can you, therefore, deny the claim of 

 being a man of action to Galileo, can you deny it to Pasteur, Kelvin, 

 Lister, and a host of others? There are, no doubt, philosophers who 

 cannot manage even their own affairs, and whom it would be correct 

 to call pure theorists, but that proves nothing, because their defect 

 makes them worse philosophers as well as worse citizens. 



In his Presidential Address, delivered to this Association in 1899, 

 Sir Michael Foster summarized the essential features of the scientific 

 mind. Above all other things he considered that its nature should be 

 such as to vibrate in unison with what it is in search of ; further, it 

 must possess alertness, and finally moral courage. Yet after enumerat- 

 ing these qualities, he arrives at the same result which I have tried to 

 place before you, that there are no special peculiarities inherent in the 

 scientific mind, and he expresses this conclusion in the following words : 

 ' But, I hear some one say, these qualities are not the peculiar attri- 

 butes of the man of science, they may be recognized as belonging to 

 almost everyone who has commanded or deserved success, whatever 

 may have been his walk in life. That is so. That is exactly what I 

 would desire to insist, that the men of science have no peculiar virtues, 

 no special powers. They are ordinary men, their characters are 

 common, even commonplace. Science, as Huxley said, is organized 

 common-sense, and men of science are common men drilled in the 

 ways of common-sense.' 



This saying of Huxley's has been repeated so often that one 

 almost wishes it were true, but unfortunately I cannot find a 

 definition of common-sense that fits the phrase. Sometimes the word 

 is used as if it were identical with uncommon sense, sometimes as if it 

 were the same thing as common nonseyise. Often it means untrained 

 intelligence, and in its best aspect it is, I think, that faculty which 

 recognizes that the obvious solution of a problem is frequently the right 

 one. "When, for instance, I see, during a total solar eclipse, red flames 

 .shooting out from the edge of the sun, the obvious explanation is that 



