Beneath all these changes there is an enduring "something." There are abiding constants as well as fleeting changes; enduring realities as well as unstable phenomena. The same forms and relations, the same forces and laws, the same analogous functions, and the same archetypal ideas, remain amid all individual changes. There is an enduring _substance_ which is the subject of all these changes. There is a permanent force, or _power_, which is the cause of all change. There are constant numerical proportions, determinate geometrical forms, specific ideal archetypes, and special ends, which give the law of all change. The universe is not a mere aggregation of phenomena, a mere concourse of things in time and space with accidental resemblances: it is a _unity_, a cosmos, a harmonious whole, both in its contemporaneous and successive history. So much is and always has been known, with more or less clearness and distinctness by all men, and known by a spontaneous and immediate intuition. This intuition, like every intuition, even the commonest intuition of sense, has had a gradual development both in the consciousness of the individual, and in the consciousness of the race. It has always been immanent in human thought even when not articulately expressed in human language. To the native common-sense of our race, the world is a reality, not a dream; to the universal reason of mankind the universe is a harmony, not a chaos. Men have instinctively apprehended some ideal relations, some causal connection, some adaptation and purpose in nature, and they have always had some intuition, however dim and shadowy, of an _all-pervading unity_, and an _ultimate causative principle_. But when the universe has become the object of _reflective_ thought, when man has attempted a colligation of the individual facts, and an ideal construction and rational interpretation of the phenomena, when he has sought to grasp the manifoldness and diversity of nature in a higher unity of thought, and, above all, when he has attempted to pass beyond phenomena and their relations, and form a conception of _the absolute reality and ultimate cause_--then it is that difficulties have arisen and questions have presented themselves which have perplexed the discursive reason, and taxed the genius of the ablest thinkers of every age. 1. First of all, there have arisen the fundamental questions: Has the universe always existed, or had the Cosmos, with its changes and constants, its forces and laws, its forms and relations, a _Beginning_? Is its present condition but one link in an endless chain, one phasis in a series of changes, which had no beginning and shall have no end? Is the universe limited both in space and duration, or is it unlimited, unbeginning, and endless?