It is admitted that when Christianity had been for some time at work in the world, this ancient servile status began in some mysterious manner to disappear. I suggest here that one of the forms which the new spirit took was the importance of the vow. Feudalism, for instance, differed from slavery chiefly because feudalism was a vow. The vassal put his hands in those of his lord, and vowed to be his man; but there was an accent on the noun substantive as well as on the possessive pronoun. By swearing to be his man, he proved he was not his chattel. Nobody exacts a promise from a pickaxe, or expects a poker to swear everlasting friendship with the tongs. Nobody takes the word of a spade; and nobody ever took the word of a slave. It marks at least a special stage of transition that the form of freedom was essential to the fact of service, or even of servitude. In this way it is not a coincidence that the word homage actually means manhood. And if there was vow instead of status even in the static parts of Feudalism, it is needless to say that there was a wilder luxuriance of vows in the more adventurous part of it. The whole of what we call chivalry was one great vow. Vows of chivalry varied infinitely from the most solid to the most fantastic; from a vow to give all the spoils of conquest to the poor to a vow to refrain from shaving until the first glimpse of Jerusalem. As I have remarked, this rule of loyalty, even in the unruly exceptions which proved the rule, ran through all the romances and songs of the troubadours; and there were always vows even when they were very far from being marriage vows. The idea is as much present in what they called the Gay Science, of love, as in what they called the Divine Science, of theology. The modern reader will smile at the mention of these things as sciences; and will turn to the study of sociology, ethnology and psycho-analysis; for if these are sciences (about which I would not divulge a doubt) at least nobody would insult them by calling them either gay or divine.