It is a postulate, with many writers of this day, that the late War was the result of two opposing ideas, or principles, upon subject of African Slavery. Between these, according to their theory, sprung the “irrepressible conflict,” in principle, which ended in the terrible conflict of arms. Those who assume this postulate, and so theorize upon it, are but superficial observers.

That the War had its origin in opposing principles, which, in their action upon the conduct of men, produced the ultimate collision of arms, may be assumed as an unquestionable fact. But the opposing principles which produced these results in physical action were of a very different character from those assumed in the postulate. They lay in the organic Structure of the Government of the States. The conflict in principle arose from different and opposing ideas as to the nature of what is known as the General Government. The contest was between those who held it to be strictly Federal in its character, and those who maintained that it was thoroughly National. It was a strife between the principles of Federation, on the one side, and Centralism, or Consolidation, on the other.

Slavery, so called, was but the question on which these antagonistic principles, which had been in conflict, from the beginning, on divers[e] other questions, were finally brought into actual and active collision with each other on the field of battle.

Source: Alexander Stephens, A Constitutional View of the Late War Between the States (Philadelphia: National Publishing Co., 1868), 9–10.