The philosophy of Locke, which attempted to lay a basis for knowledge in psychology, coincided with, where it did not create, this general attempt to appeal on every subject to ultimate principles of reason. This tone in truth marked the age, and acting in every region of thought, affected alike the orthodox and the unbelieving. Accordingly, as we pass away from the speculations which mark the early period of deism to those which belong to its maturity, we find that the attack on Christianity is less suggested by political considerations, and more entirely depends on an appeal to reason, intellectual or moral.
The principal phases belonging to this period of the maturity of deism, which we shall now successively encounter, are four:
(1) An examination of the first principles of religion, on its dogmatic or theological side, with a view of asserting the supremacy of reason to interpret all mysteries, and defending absolute toleration of free thought. This tendency is seen in Toland and Collins,
(2) An examination of religion on the ethical side occurs, with the object of asserting the supremacy of natural ethics as a rule of conduct, and denying the motive of reward or punishment implied in dependent morality. This is seen in Lord Shaftesbury.
After the attack has thus been opened against revealed religion, by creating prepossessions against mystery in dogma and the existence of religious motives in morals, there follows a direct approach against the outworks of it by an attack on the evidences,
(3) In an examination, critical rather than philosophical, of the prophecies of the Old Testament by Collins, and of the miracles of the New by Woolston.
The deist next approaches as it were within the fortress, and advances against the doctrines of revealed religion; and we find accordingly,
(4) A general view of natural religion, in which the various differences,—speculative, moral, and critical, are combined, as in Tindal; or with a more especial reference to the Old Testament as in Morgan, and the New as in Chubb; the aim of each being constructive as well as destructive; to point out the absolute sufficiency of natural religion and of the moral sense as religious guides, and the impossibility of accepting as obligatory that which adds to or contradicts them; and accordingly they point out the elements in Christianity which they consider can be retained as absolutely true.
The first two of these attacks occur in the first two decades of the century: the two latter in the period from 1720 to 1740, when the public mind not being diverted by foreign war or internal sedition, and other controversies being closed, the deist controversy was at its height. After examining these, other tendencies will meet us, when we trace the decline of deism in Bolingbroke and Hume.
The first of these tendencies just noticed is seen in Toland,[391] who directed his speculations to the ground principles of revealed theology,[392] and slightly to the history of the Canon.[393]