many cases either entirely replaced or profoundly modified the theistic strain in Christianity. In current philosophy pantheism appears in the epistemological argument which identifies God with being; while the chief bulwark of theism is the ethical argument, with its provision for a distinction between the actual world and ideal principle of evolution. [Sidenote: Deism.] § 92. While theism and pantheism appear to be permanent phases in the philosophy of religion, _deism_ is the peculiar product of the eighteenth century. It is based upon a repudiation of supernaturalism and "enthusiasm," on the one hand, and a literal acceptance of the cosmological and teleological proofs on the other. Religions, like all else, were required, in this epoch of clear thinking, to submit to the canons of experimental observation and practical common sense. These authorize only a _natural religion_, the acknowledgment in pious living of a God who, having contrived this natural world, has given it over to the rule, not of priests and prophets, but of natural law. The artificiality of its conception of God, and the calculating spirit of its piety, make deism a much less genuine expression of the religious experience than either the moral chivalry of theism or the intellectual and mystical exaltation of pantheism. [Sidenote: Metaphysics and Theology.] § 93. The systematic development of philosophy leads to the inclusion of conceptions of God within the problem of metaphysics, and the subordination of the proof of God to the determination of the fundamental principle of reality. There will always remain, however, an outstanding theological discipline, whose function it is to interpret worship, or the living religious attitude, in terms of the theoretical principles of philosophy. [Sidenote: Psychology is the Theory of the Soul.]