§ 171. Absolute idealism is the most elaborately constructive of all the historical types of philosophy. Though it may have overlooked elementary truths, and have sought to combine irreconcilable principles, it cannot be charged with lack of sophistication or subtlety. Its great virtue is its recognition of problems--its exceeding circumspection; while its great promise is due to its comprehensiveness--its generous provision for all interests and points of view. But its very breadth and complexity render this philosophy peculiarly liable to the equivocal use of conceptions. This may be readily understood from the nature of the central doctrine of absolute idealism. According to this doctrine it is proposed to define the universe as an _absolute spirit_; or a being infinite, ultimate, eternal, and self-sufficient, like the being of Plato and Spinoza, but possessing at the same time the distinguishing properties of spirit. Such conceptions as self-consciousness, will, knowledge, and moral goodness are carried over from the realm of human endeavor and social relations to the unitary and all-inclusive reality. Now it has been objected that this procedure is either meaningless, in that it so applies the term spirit as to contradict its meaning; or prejudicial to spiritual interests, in that it neutralizes the properties of spirit through so extending their use. Thus one may contend that to affirm that the universe as a whole is spirit is meaningless, since moral goodness requires special conditions and relations that cannot be attributed to the universe as a whole; or one may contend that such doctrine is prejudicial to moral interests because by attributing spiritual perfection to the totality of being it discredits all moral loyalties and antagonisms. The difficulties that lie in the way of absolute idealism are due, then, to the complexity of its synthesis, to its complementary recognition of differences and resolution of them into unity. But this synthesis is due to the urgency of certain great problems which the first or realistic expression of the absolutist motive left undiscovered and unsolved. [Sidenote: The Great Outstanding Problems of Absolutism.]