Mr. Greeley's volume is a valuable contribution to our political history. Though for many years well known as an ardent politician, and associated by popular prejudice with that class of untried social theories which are known by the name of _isms_, his tone is singularly calm and dispassionate. Disfigured here and there by a vulgarism which adds nothing to its point, while it detracts from its purity, his style is clear, straightforward, and masculine,--a good business style, at once bare of ornament and undiluted with eloquence. Mr. Greeley's intimate knowledge of our politics and instinctive sympathy with the far-reaching scope of our institutions (for, as Beranger said of himself, he is _tout peuple_) admirably fitted him for his task. He is clear, concise, and accurate, honestly striving after the truth, while his judicious Preface shows that he appreciates fully the difficulties that beset whoever seeks to find it. If none of his readers will be surprised to find his work that of an able man, there are many who would not expect it to be, as it is, that of a fair-minded one. He writes without passion, making due allowance for human nature in the South as well as the North, and does not waste his strength, as is the manner of fanatics, in fighting imaginary giants while a real enemy is in the field. Tracing Secession to its twin sources in slavery and the doctrine of State Rights, and amply sustaining his statements of fact by citations from contemporary documents and speeches, he has made the plainest, and for that very reason, we think, the strongest, argument that has been put forth on the national side of the question at issue in our civil war. Above all, he is ready to allow those virtues in the character of the Southern people whose existence alone makes reunion desirable or possible. We should not forget that the Negro is at least no more our brother than they, for if he have fallen among thieves who have robbed him of his manhood, they have been equally enslaved by prejudice, ignorance, and social inferiority.