Of _The Letters on Toleration_, though deeply interesting to the generation in which they were written, a very brief account will here suffice. Their main thesis is, that the jurisdiction of the civil magistrate does not extend to the regulation of religious worship or to controlling the expression of religious beliefs, except so far as that worship or those beliefs may interfere with the ends of civil government. The respective provinces of a commonwealth and a church are strictly defined, and are shown to be perfectly distinct. "The boundaries on both sides are fixed and immovable. He jumbles heaven and earth together, the things most remote and opposite, who mixes these societies, which are in their original, end, business, and in everything, perfectly distinct and infinitely different from each other." But it may be asked, are there no speculative opinions, no tenets, actual or possible, of any religious community which should be restrained by the Civil Magistrate? The answer is, yes,-- "First, No opinions contrary to human society, or to those moral rules which are necessary to the preservation of civil society, are to be tolerated by the magistrate." Secondly, after speaking of those who maintain such positions as that "faith is not to be kept with heretics," that "kings excommunicated forfeit their crowns and kingdoms," that "dominion is founded in grace," he proceeds: "These, therefore, and the like, who attribute unto the faithful, religious, and orthodox, that is, in plain terms, unto themselves, any peculiar privilege or power above other mortals in civil concernments, or who, upon pretence of religion, do challenge any manner of authority over such as are not associated with them in their ecclesiastical communion: I say these have no right to be tolerated by the magistrate, as neither those that will not own and teach the duty of tolerating all men in matters of mere religion. For what do all these and the like doctrines signify, but that they may, and are ready upon any occasion to seize the government, and possess themselves of the estates and fortunes of their fellow-subjects, and that they only ask leave to be tolerated by the magistrates so long until they find themselves strong enough to effect it?" "Thirdly, That church can have no right to be tolerated by the magistrate, which is constituted upon such a bottom that all those who enter upon it do thereby ipso facto deliver themselves up to the protection and service of another prince. For by this means the magistrate would give way to the settling of a foreign jurisdiction in his own country, and suffer his own people to be listed, as it were, for soldiers against his own government."