In a long autobiographic passage in the _Second Defence of the People of England_ Milton makes a formal classification of his prose works written before that date. All of them, he says, were designed to promote Liberty. By the accidents of the time he was induced to treat first, in his anti-episcopal pamphlets, of religious liberty. Once that controversy was fairly ablaze, in the name of the same goddess he applied his incendiary torch to humbler piles. "I perceived," he says, "that there were three species of liberty which are essential to the happiness of social life--religious, domestic, and civil; and as I had already written concerning the first, and the magistrates were strenuously active in obtaining the third, I determined to turn my attention to the second, or the domestic species." He includes in this division of his work the Divorce pamphlets, the tractate _Of Education_, and the _Areopagitica_, as dealing with the "three material questions" (so he calls them) of domestic liberty, namely, "the conditions of the conjugal tie, the education of the children, and the free publication of the thoughts." It seems a strange conception of domestic liberty which makes it rest on a threefold support--divorce at will, an unrestrained printing-press, and the encyclopaedic education of polyglot children. But the truth is that Milton's classification is an after-thought. The pamphlets that he names were all written by him much about the same time, between 1643 and 1645; but the true history of their origin is more interesting and less symmetrical than the later invented scheme of classification. The Divorce pamphlets were written because Milton was unhappily married. The _Areopagitica_ was written because his heterodox views concerning marriage had brought him into collision with the Presbyterian censors of the press. His treatise on education was written because he had undertaken the education of his own nephews, and had become deeply interested in that question. In all three his own experience is the first motive; in all three that experience is concealed beneath a formidable array of general considerations, dogmatically propounded.