16 



INTRODUCTION. 



26. 



Unity of 

 Thought a 

 product 

 of this r 

 century. 



27. 



Voltaire. 



28. 



Adam 

 Smith. 



this subject is by the limits of time and space which I 

 have mentioned, it is, nevertheless, still vast, intricate, and 

 bewildering. And yet it is' my intention, throughout the 

 inquiries which I have to institute and in the various out- 

 lines and sketches which I have to draw, never to lose 

 sight of the unity of the whole. This unity, I maintain, 

 the progress of our age has more and more forced upon 

 us. It is itself a result of th'e work of the century. A 

 hundred years even fifty years ago, it would have been 

 impossible to speak of European Thought in the manner in 

 which I do now. For the seventeenth and eighteenth 

 centuries mark the period in which, owing to the use of 

 the several vernacular languages of Europe in the place 

 of the mediaeval Latin, thought became nationalised, in 

 which there grew up first the separate literatures and then 

 the separate thought of the different civilised countries of 

 Western Europe. Thus it was that in the last century, 

 and at the beginning of this, people could make journeys 

 of exploration in the region of thought from one country 

 to another, bringing home with them new and fresh ideas. 

 Such journeys of discovery, followed by importation of new 

 ideas, were those of Voltaire l to England in 1726, where 

 he found the philosophy of Newton and Locke, at that 

 time not known and therefore not popularly appreciated 

 in France ; the journey of Adam Smith in 1765 to France, 

 where he became acquainted with the economic system of 

 Quesnay and the opinions of the so-called " physiocrats," 

 which formed the starting-point of his own great work, 



1 For a most complete collection 

 of data referring to this subject 

 see Du Bois-Reymond's address in 



the Berlin Academy, 30th January 

 1868, reprinted in the collection of 

 his 'Reden,' Leipzig, 1886, vol. i. 



