44 HISTORY OF INDUCTIVE SCIENCES. 



this day, the tribes of uncivilized and half-civilized man, over the 

 whole face of the earth, have before their eyes a vast body of facts, of 

 exactly the same nature as those with which Europe has built the 

 stately fabric of her physical philosophy ; but, in almost every other 

 part of the earth, the process of the intellect by which these facts 

 become science, is unknown. The scientific faculty does not work. 

 The scattered stones are there, but the builder's hand is wanting. 

 And again, we have no lack of proof that mere activity of thought is 

 equally inefficient in producing real knowledge. Almost the whole of 

 the career of the Greek schools of philosophy ; of the schoolmen of 

 Europe in the middle ages ; of the Arabian and Indian philosophers ; 

 shows us that we may have extreme ingenuity and subtlety, invention 

 and connection, demonstration and method ; and yet that out of these 

 germs, no physical science may be developed. We may obtain, by 

 such means, Logic and Metaphysics, and even Geometry and Algebra ; 

 but out of such materials we shall never form Mechanics and Optics, 

 Chemistry and Physiology. How impossible the formation of these 

 sciences is without a constant and careful reference to observation and 

 experiment ; how rapid and prosperous their progress may be when 

 they draw from such sources the materials on which the mind of the 

 philosopher employs itself ; the history of those branches of knowl- 

 edge for the last three hundred years abundantly teaches us. 



Accordingly, the existence of clear Ideas applied to distinct Facts 

 will be discernible in the History of Science, whenever any marked 

 advance takes place. And, in tracing the progress of the various prov- 

 inces of knowledge which come under our survey, it will be important 

 for us to see that, at all such epochs, such a combination has occurred; 

 that whenever any material step in general knowledge has been made, 

 whenever any philosophical discovery arrests our attention, some 

 man or men come before us, who have possessed, in an eminent degree, 

 a clearness of the ideas which belong, to the subject in question, and 

 who have applied such ideas in a vigorous and distinct manner to 

 ascertained facts and exact observations. TV r e shall never proceed 

 through any considerable range of our .narrative, without having occa- 

 sion to remind the reader of this reflection. 



Successive Steps in Science. But there is another remark which 

 we must also make. Such sciences as we have here to do with are 



* Concerning Successive Generalizations in Science, see the Philosophy, book 5. ch. 

 2, sect. 11. 



