You are in a square room with a high ceiling, and from the middle of the ceiling hangs a wire with a heavy ball at its lower end, so as to make a sort of pendulum. Only, instead of swinging to and fro in a straight line, the ball moves round and round in a circle. On one wall of the room a bright light throws a shadow of the wire and ball; and this shadow represents exactly the motion of an ordinary pendulum swinging to and fro in simple harmonic motion. Now, if you are a being who lives in shadow-land, you will say that this represents alternation, cyclic ebb and flow, the perpetual vibration between pleasure and pain, good fortune and ill, that constitutes the drama of human life. And truly it is a symbol of the course of Nature in general on the lower planes of manifestation. Yet, look at the real pendulum itself: there is no alternation there, no periodicity. The motion of the ball is uniform and invariable, it is the same at every part, every moment, of its path. Considered apart from its surroundings, there is no point which can be called a beginning, no point which can be called an end; so that no question of period can be raised.
Here we have an illustration of time and that which is beyond time. Some call the latter duration, others may prefer to call it eternity. Time, as we know it, is divided; divided into periods which have definite relative lengths. But that which is beyond time is not divided. Yet our illustration shows that the undivided duration is parent to the divided time. The latter is produced from the former by a shadow on a wall; it is the material world which splits up infinitude into finitude. The motion of the circular pendulum is uniform and invariable; the motion of its shadow is alternately accelerated and retarded; there are points where it comes to a stop and turns back.
This kind of illustration is not fanciful but real; for it means "as above, so below." Doubtless an indefinite number of other illustrations of this same principle could be found in the physical world. Periodicity born out of invariability, multiplicity out of unity. We see that temporal life, instead of being comprehended in a single and whole view, is spread out in a long series of successive scenes. Perhaps the life-view experienced at critical moments of death or birth is rather a single entire vision than a succession of glimpses. Other thoughts will be suggested, but we should beware of pushing an analogy too far; because any one analogy illustrates some one particular aspect of the question, and if we forget other analogies which illustrate other aspects, we shall land in absurdities. There are not simply two planes in Nature, one right and the other wrong: there are many planes, and the terms "real" and "unreal" must be used relatively. Neglect of this precaution is mainly responsible for our difficulty in reconciling prevision with freewill.