INTRODUCTORY. 29 



attainable by us. Now, our most careful and complete 

 investigations in all departments of nature are science — 

 physical sciences of different kinds— but they are not 

 and cannot be the highest science, or science par 

 excellence^ for they do not embody the " most certain 

 knowledge." Observations and experiments are of the 

 greatest value ; nevertheless, in the last resort, when we 

 have done observing and experimenting, we depend for 

 the result entirely on our knowledge of absolute and 

 necessary truths. Were it not for our implicit know- 

 ledge of such truths, we could not know that we had 

 ascertained the facts we had ascertained ; neither could 

 we know their necessary bearings and the most certain 

 deductions from them. 



Science has to do with self-evident, necessary truths 

 — first principles which underlie and maintain every 

 kind of physical science. When, then, truths seen by 

 the intellect to contain their own evidence, or which 

 result from reasoning logically carried on, are declared 

 to be uncertain, or even false, because they do not agree 

 with what is (by a confusion of terms) called " the 

 scientific imagination," as great an absurdity is com- 

 mitted as if it were said that it must be false that any 

 vessel has gone directly against the wind, because a 

 sailing vessel is unable so to do. 



It is, of course, true that mechanical conceptions 

 have been and are of great utility. It is, therefore, not 

 only permissible, but laudable, to make use of them as 

 working hypotheses. But it is a very different thing 

 to represent them as absolute truths. Yet much of 

 what is often spoken of as "science" is really un- 



