§ [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.
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.
Psychology is the Theory of the Soul.
§ [94]. Psychology is the theory of the soul. As we have already seen, the rise of scepticism directs attention from the object of thought to the thinker, and so emphasizes the self as a field for theoretical investigation. But the original and the dominating interest in the self is a practical one. The precept, γνῶθι σεαυτόν, has its deepest justification in the concern for the salvation of one's soul. In primitive and half-instinctive belief the self is recognized in practical relations. In its animistic phase this belief admitted of such relations with all living creatures, and extended the conception of life very generally to natural processes. Thus in the beginning the self was doubtless indistinguishable from the vital principle. In the first treatise on psychology, the "περὶ Ψυχῆς" of Aristotle, this interpretation finds a place in theoretical philosophy. For Aristotle the soul is the entelechy of the body—that function or activity which makes a man of it. He recognized, furthermore, three stages in this activity: the nutritive, sensitive, and rational souls, or the vegetable, animal, and distinctively human natures, respectively. The rational soul, in its own proper activity, is man's highest prerogative, the soul to be saved. By virtue of it man rises above bodily conditions, and lays hold on the divine and eternal. But Plato, who, as we have seen, was ever ready to grant reality to the ideal apart from the circumstances of its particular embodiment, had already undertaken to demonstrate the immortality of the soul on the ground of its distinctive nature.[209:16] According to his way of thinking, the soul's essentially moral nature made it incapable of destruction through the operation of natural causes. It is evident, then, that there were already ideas in vogue capable of interpreting the Christian teaching concerning the existence of a soul, or of an inner essence of man capable of being made an object of divine interest.
Spiritual Substance
§ [95]. The immediate effect of Christianity was to introduce into philosophy as one of its cardinal doctrines the theory of a spiritual being, constituting the true self of the individual, and separable from the body. The difference recognized in Plato and Aristotle between the divine spark and the appetitive and perceptual parts of human nature was now emphasized. The former (frequently called the "spirit," to distinguish it from the lower soul) was defined as a substance having the attributes of thought and will. The fundamental argument for its existence was the immediate appeal to self-consciousness; and it was further defined as indestructible on the ground of its being utterly discontinuous and incommensurable with its material environment. This theory survives at the present day in the conception of pure activity, but on the whole the attributes of the soul have superseded its substance.
Intellectualism and Voluntarism.
§ [96]. Intellectualism and voluntarism are the two rival possibilities of emphasis when the soul is defined in terms of its known activities. Wherever the essence of personality is in question, as also occurs in the case of theology, thought and will present their respective claims to the place of first importance. Intellectualism would make will merely the concluding phase of thought, while voluntarism would reduce thought to one of the interests of a general appetency. It is evident that idealistic theories will be much concerned with this question of priority. It is also true, though less evident, that intellectualism, since it emphasizes the general and objective features of the mind, tends to subordinate the individual to the universal; while voluntarism, emphasizing desire and action, is relatively individualistic, and so, since there are many individuals, also pluralistic.[211:17]
Freedom of the Will. Necessitarianism, Determinism, and Indeterminism.