Involved in this problem of African slavery was the incidental issue of Free Trade and Protection,--apparently only economical and industrial in character, but in reality fundamentally crucial. And behind this lay the constitutional question, involving as it did not only the conflicting theories of a strict or liberal construction of the fundamental law, but nationality also,--the right of a Sovereign State to withdraw from the Union created in 1787, and developed through two generations. These may be termed concrete political issues, as opposed to basic truths generally accepted and theories individually entertained. The theories were constitutional, social, economical. Constitutionally, they turned upon the obligations of citizenship. There was no such thing then as a citizen of the United States of and by itself. The citizen of the United States was such simply because of his citizenship of a Sovereign State,--whether Massachusetts or Virginia or South Carolina; and, of course, an instrument based upon a divided sovereignty admitted of almost infinitely diverse interpretation. It is a scriptural aphorism that no man can serve two masters; for either he will hate the one and love the other, or else he will hold to the one and despise the other. And in the fulness of time it literally with us so came about. The accepted economical theories of the period were to a large extent corollaries of the fundamental proposition, and differing material and social conditions. Beyond all this, and coming still under the head of individual theories, was the doctrine enunciated by Thomas Jefferson in the Declaration of Independence,--the doctrine that all men were created equal,--meaning, of course, equal before the law. But the theorist and humanitarian of the North, accepting the fundamental principle laid down in the Declaration, gave to it a far wider application than had been intended by its authors,--a breadth of application it would not bear. Such science as he had being of scriptural origin, he interpreted the word "equal" as signifying equal in the possibilities of their attributes,--physical, moral, intellectual; and in so doing, he of course ignored the first principles of ethnology. It was, I now realize, a somewhat wild-eyed school of philosophy, that of which I myself was a youthful disciple.