PREFACE. 



materials that I had collected in a separate book, under the title of " A 

 History of the Intellectual Development of Europe." The object of 

 this was mainly to point out that the intellectual progress of nations 

 proceeds in the same course as the intellectual development of the indi- 

 vidual ; that the movement of both is not fortuitous, but under the 

 dominion of law ; that the stages of personal development are paralleled 

 by the stages of social development, and, indeed, as palaeontology has 

 proved, by the evolution of all animated nature ; that there is an ascent 

 of man through well-marked epochs from the most barbarous to the most 

 highly civilized condition. This book was translated into many lan- 

 guages : in some of them several editions of it were issued. Portions 

 of it relating to Mohammedan science were translated into Arabic. 



About this time, circumstances led me to deliver before the New York 

 Historical Society a course of lectures on American topics, considered 

 from a similar point of view. These were enlarged, and published un- 

 der the title of "Thoughts on the Civil Policy of America." This, like 

 the preceding, was extensively translated and circulated. The train of 

 investigation on which I had thus entered led me to a far more serious 

 undertaking a " History of the American Civil War," which had just 

 then closed. To this, moreover, I was incited by the earnest request of 

 some who had been chief actors in the events, and who ve"ry effectively 

 aided me. I had the inestimable advantage of enjoying the friendship 

 of many whose names have now become illustrious in connection with 

 those times. The Secretary of War gave me access to the public docu- 

 ments on both sides, and to him I was indebted for guidance in the de- 

 scription of many of the most important incidents and the course of na- 

 tional policy. To generals who had commanded in great battles and 

 conducted great campaigns I owed information which they alone could 

 impart, and, in like manner, most valuable assistance was given me in 

 special cases by persons eminent in military and civil life. It is often 

 said that the history of any very great social event cannot be correctly 

 written by a contemporaneous author, and that we must wait until 

 passions have subsided and interests ceased for a narrative of the truth. 

 But this is not so. More depends on the impartiality of the writer than 

 on the deadening lapse of time. The best history will always be written 

 by one who has had the best opportunity of getting at the facts, who 

 has had the privilege of the friendship or personal acquaintance of those 

 who have been conspicuous in the events. 



No one can consider the intellectual development of Europe without 

 contemplating the forces that have brought that continent to its present 

 social condition forces that have never ceased to be in active opposition. 

 Under the title of a " History of the Conflict of Religion and Science," 



