The true nature of causation must be regarded as the fundamental problem of science, for we can never know anything but causes and effects. They are correlatives in language and in thought. To the question—What is causation?—four answers can be given: (1) the sceptical, (2) the material, (3) the pantheistic, (4) the rational or Christian. To assert that man is utterly ignorant of the true nature of causation is total scepticism. To predicate the doctrine of invariable sequence, as did Hume and Brown, presents the formula of materialism, of which idealism is another phase. Idealism and materialism are identical at the root.2 Both take it for granted that all
Nature is but a dream-show, where phenomena are interlinked only by the bond of antecedent and consequent. If we answer that emanation is the only causation, we are landed in pantheism, where all individual existence vanishes, all notion of right and wrong, truth and falsehood. The remaining answer is that which I deem rational, Christian and true—that causation resides in mind, that matter can never be a cause, and that every phenomenon is the effect of intellectual force exerted by pure volition. This view it is now proposed to demonstrate after the rigorous method of geometricians. It may be laid down as a general proposition that the perception of mathematical truth is essentially an attribute of intellect. It follows that to work mathematically evinces mind. Now, all motions of the material universe, in their wondrous variety and unity, are strictly mathematical. I will begin with my own organism. I survey my right hand: it has five fingers. I look at my left: this has five also. I turn to each foot and on each behold five toes. I think of my bodily senses: these are five again. Throughout all members of my body there runs also a wondrous duality—in my eyes, arms, hands, feet, ribs and the convolutions of my brain, where equal members balance each other. If the Cause which arranged the relations of my several organs understand mathematical harmonies, all is luminous. There is no chance to be calculated against their production, since He who comprehends the relations of number can involve them indefinitely and even infinitely, supposing that He is Himself infinite. But if the Cause which produces the combinations be not mathematical mind, what are the chances against a single combination of fives in a pair? And what are they in respect of the millions now living, as of all that have lived and passed
away? The algebra of an archangel, with infinite space for his sheet and eternity for the period of solution, might be insufficient for the overwhelming computation. The question therefore recurs: could any Cause without intellect to perceive and reason to count produce these invariable equations?
We can, however, carry the demonstration that all motions in Nature are mathematical through the whole field of phenomena. We may take the invariable ratio between the hydrogen and oxygen in water, of oxygen and nitrogen in atmospheric air, of oxygen and carbon in carbonic acid. Here are a few fragments of the evidence drawn from chemistry. In botany we may take the first two classes of Linnaeus, arranged according to the number of stamens in each flower. We may analyse a flower of the tobacco plant. It is of the fifth class and has therefore five stamens; its corolla has five parts and its calyx five points. It is so with every tobacco flower on earth: so it has ever been and so will remain always. We may appeal to the phenomena of light, that wonderful agent which plays so important a part in the processes of creation. We may confine ourselves to the strict algebraic formula of its first law—that the intensity of light decreases as the square of its distance increases, and vice versa. So also the second law, that the angles of incidence and reflection are always equal. Is it possible that the Cause which thus geometrises is devoid of all knowledge of geometry? Were there no other proof of the existence of Deity, there is one other consideration in the domain of light which should settle the question for ever. It is this—that every rainbow is an exact mathematical equation of every other rainbow in the universe.1 But there is finally the science of as-
tronomy, which is another name for sublimity itself, and there are the three great laws of Kepler: (1) That all planetary orbits are regular ellipses, in the lower focus of which the sun is placed; (2) that the times occupied by any planet, in describing any given arcs of its orbit, are always as the areas of sectors, formed by straight lines drawn from the beginning and end of the arcs to the sun, as a centre; (3) that the squares of the periods of the planet's revolutions vary, as the cubes of their distance from the sun. We are taught in this manner that nothing but mathematical harmony obtains in all motions within our own sphere. We can conceive of nothing but mathematical harmony in any other region, and as nothing but mind can work mathematically, we behold, everywhere about us, the unequivocal footsteps of a God. It follows that every effect in the universe is produced by the immediate agency of Mind. Matter and Mind are two logical categories which encompass all thought and exhaust all Nature. But matter being passive and unable therefore to originate its own motions, without which no effect can occur in Nature, our search after causal force must be carried into the domain of mind.1 That it is found
there is confirmed by our inner consciousness, in the motions of its voluntary activity. Our argument is directed to the present, to things as they now are, to the sublime evolutions manifested before our eyes, and it is proved to us that God is. But it is directed also to the past, and it is demonstrated that He was then, while the eternal uniformity of Nature leads us to a not less certain inference—that He will continue for ever. There is indeed no past or future. The faith that asserts God proclaims all things present to the soul. We repose on the bosom of our Father with a confidence that nothing can shake. Friends may grow cold and change around us; enemies may combine for our destruction; but we have our immortal Friend, encircling our souls in arms of everlasting love. Then "will I trust Him, though He slay me." On the summit of this exalted faith, which is certainty, I rest secure. Nothing can move me more. The sensuous world has vanished from beneath my feet. I live already in the Spirit Land. The immortal dead are around me. I hear them holding high converse in translucent clouds. It is no night's vision, though brighter than all dreams. I am son and heir of universal empire. I have found God, Who owneth all. The vessel in which I have embarked may drift whithersoever it will on the immeasurable sea of being. Impenetrable clouds may hide the stars of heaven; but God guides the storm. Lightnings may rend my sails, but on whatsoever shore the wreck of my barque is strewn, He is sure to be there, with all my love and all my hopes around Him. There where He is it is an open gate of heaven, for there is the Everlasting Love, and love is heaven.