It maybe doubted whether Bolingbroke (died 1751; cf. p. 203) is to be classed among the deists or among their opponents. On the one hand, he finds in monotheism the original true religion, which has degenerated into superstition through priestly cunning and fantastical philosophy; in primitive Christianity, the system of natural religion, which has been transformed into a complicated and contentious science by its weak, foolish, or deceitful adherents; in theology, the corruption of religion; in Bacon, Descartes, and Locke, types of untrammeled investigation. On the other hand, he seeks to protect revelation from the reason whose cultivation he has just commended, and to keep faith and knowledge distinct, while he demands that the Bible, with all the undemonstrable and absurd elements which it contains, be accepted on its own authority. Religion is an instrument indispensable to the government for keeping the people in subjection. Only the fear of a higher power, not the reason, holds the masses in check; and the freethinkers do wrong in taking a bit out of the mouth of the sensual multitude, when it were better to add to those already there. As Hume, the skeptic, leads empiricism to its fall, so Hume, the philosopher of religion (see below), leads deism toward dissolution. Among those who defended revealed Christianity against the deistical attacks we may mention the names of Conybeare (1732) and Joseph Butler (1736). The former argues from the imperfection and mutability of our reason to like characteristics in natural religion. Butler (cf. p. 206) does not admit that natural and revealed religion are mutually exclusive. Christian revelation lends a higher authority to natural religion, in which she finds her foundation, and adapts it to the given relations and needs of mankind, adding, however, to the rational law of virtue new duties toward God the Son and God the Holy Ghost. It is evident that in order to be able to deal with their opponents, the apologetes are forced to accommodate themselves to the deistic principle of a rational criticism of revelation. Notwithstanding the fear which this principle inspired in the men of the time, it soon penetrated the thought even of its opponents, and found its way into the popular mind through the channels of the Illumination.