The word "substance" means that which stands under and supports anything else. Whatever then creates, upholds, classifies anything which our senses behold, though we can not handle, see, taste or smell it, is more substantial than the object itself. In this way the soul which vivifies, moves and supports the body is a more potent substance than the hard bones and heavy flesh which it vitalizes. A ten-pound weight falling on your head affects you unpleasantly as substance, much more so than a leaf of the New Testament, if dropped in the same direction; but there is a way in which a page of the New Testament may fall upon a nation and split it, or infuse itself into its bulk and give it strength and permanence. We should be careful, therefore, what test we adopt in order to decide the relative stability of things.
There is a very general tendency to deny that ideal forces have any practical power. But there have been several thinkers whose skepticism has an opposite direction. "We can not," they say, "attribute external reality to the sensations we feel." We need not wonder that this theory has failed to convince the unmetaphysical common-sense of people that a stone post is merely a stubborn thought, and that the bite of a dog is nothing but an acquaintance with a pugnacious, four-footed conception. When a man falls downstairs it is not easy to convince him that his thought simply tumbles along an inclined series of perceptions and comes to a conclusion that breaks his head; least of all, can you induce a man to believe that the scolding of his wife is nothing but the buzzing of his own waspish thoughts, and her too free use of his purse only the loss of some golden fancies from his memory. We are all safe against such idealism as Bishop Berkeley reasoned out so logically. Byron's refutation of it is neat and witty:
And yet, by more satisfactory evidence than that which the idealists propose, we are warned against confounding the conception of substance with matter, and confining it to things we can see and grasp. Science steps in and shows us that the physical system of things leans on spirit. We talk of the world of matter, but there is no such world. Everything about us is a mixture or marriage of matter and spirit. A world of matter—there would be no motion, no force, no form, no order, no beauty, in the universe as it now is; organization meets us at every step and wherever we look; organization implies spirit—something that rules, disposes, penetrates and vivifies matter.
See what a sermon astronomy preaches as to the substantial power of invisible things. If the visible universe is so stupendous, what shall we think of the unseen force and vitality in whose arms all its splendors rest? It is no gigantic Atlas, as the Greeks fancied, that upholds the celestial sphere; all the constellations are kept from falling by an impalpable energy that uses no muscles and no masonry. The ancient mathematician, Archimedes, once said, "Give me a foot of ground outside the globe to stand upon, and I will make a lever that will lift the world." The invisible lever of gravitation, however, without any fulcrum or purchase, does lift the globe, and makes it waltz, too, with its blonde lunar partner, twelve hundred miles a minute to the music of the sun—ay, and heaves sun and systems and Milky Way in majestic cotillions on its ethereal floor.
You grasp an iron ball, and call it hard; it is not the iron that is hard, but cohesive force that packs the particles of metal into intense sociability. Let the force abate, and the same metal becomes like mush; let it disappear, and the ball is a heap of powder which your breath scatters in the air. If the cohesive energy in Nature should get tired and unclench its grasp of matter, our earth would instantly become "a great slump"; so that which we tread on is not material substance, but matter braced up by a spiritual substance, for which it serves as the form and show.
All the peculiarities of rock and glass, diamond, ice and crystal are due to the working of unseen military forces that employ themselves under ground—in caverns, beneath rivers, in mountain crypts, and through the coldest nights, drilling companies of atoms into crystalline battalions and squares, and every caprice of a fantastic order.
When we turn to the vegetable kingdom, is not the revelation still more wonderful? The forms which we see grow out of substances and are supported by forces which we do not see. The stuff out of which all vegetable appearances are made is reducible to oxygen, hydrogen, carbon and nitrogen. How does it happen that this common stock is worked up in such different ways? Why is a lily woven out of it in one place and a dahlia in another, a grapevine here, and a honeysuckle there—the orange in Italy, the palm in Egypt, the olive in Greece and the pine in Maine? Simply because a subtile force of a peculiar kind is at work wherever any vegetable structure adorns the ground, and takes to itself its favorite robe. We have outgrown the charming fancy of the Greeks that every tree has its Dryad that lives in it, animates it, and dies when the tree withers. But we ought, for the truth's sake, to believe that a life-spirit inhabits every flower and shrub, and protects it against the prowling forces of destruction. Look at a full-sized oak, the rooted Leviathan of the fields. Judging by your senses and by the scales, you would say that the substance of the noble tree was its bulk of bark and bough and branch and leaves and sap, the cords of woody and moist matter that compose it and make it heavy. But really its substance is that which makes it an oak, that which weaves its bark and glues it to the stem, and wraps its rings of fresh wood around the trunk every year, and pushes out its boughs and clothes its twigs with breathing leaves and sucks up nutriment from the soil continually, and makes the roots clench the ground with their fibrous fingers as a purchase against the storm, and at last holds aloft its tons of matter against the constant tug and wrath of gravitation, and swings its Briarean arms in triumph, in defiance of the gale. Were it not for this energetic essence that crouches in the acorn and stretches its limbs every year, there would be no oak; the matter that clothes it would enjoy its stupid slumber; and when the forest monarch stands up in his sinewy, lordliest pride, let the pervading life-power, and its vassal forces that weigh nothing at all, be annihilated, and the whole structure would wither in a second to inorganic dust. So every gigantic fact in Nature is the index and vesture of a gigantic force. Everything which we call organization that spots the landscape of Nature is a revelation of secret force that has been wedded to matter, and if the spiritual powers that have thus domesticated themselves around us should be canceled, the whole planet would be a huge Desert of Sahara—a bleak sand-ball, without shrub, grass-blade or moss.
As we rise in the scale of forces towards greater subtility, the forces become more important and efficient. Water is more intimately concerned with life than rock, air higher in the rank of service than water, electric and magnetic agencies more powerful than air; and light, the most delicate, is the supreme magician of all. Just think how much expenditure of mechanical strength is necessary to water a city in the hot summer months. What pumping and tugging and wearisome trudging of horses with the great sprinklers over the tedious pavement! But see by what beautiful and noiseless force Nature waters the world! The sun looks steadily on the ocean, and its beams lift lakes of water into the air, tossing it up thousands of feet with their delicate fingers, and carefully picking every grain of salt from it before they let it go. No granite reservoirs are needed to hold in the Cochituates and Crotons of the atmosphere, but the soft outlines of the clouds hem in the vast weight of the upper tides that are to cool the globe, and the winds harness themselves as steeds to the silken caldrons and hurry them along through space, while they disburse their rivers of moisture from their great height so lightly that seldom a violet is crushed by the rudeness with which the stream descends.
Our conceptions of strength and endurance are so associated with visible implements and mechanical arrangements that it is hard to divorce them, and yet the stream of electric fire that splits an ash is not a ponderable thing, and the way in which the lodestone reaches the ten-pound weight and makes it jump is not perceptible. You would think the man had pretty good molars that should gnaw a spike like a stick of candy, but a bottle of innocent-looking hydrogen-gas will chew up a piece of bar-iron as though it were some favorite Cavendish.
The prominent lesson of science to men, therefore, is faith in the intangible and invisible. Shall we talk of matter as the great reality of the world, the prominent substance? It is nothing but the battleground of terrific forces. Every particle of matter, the chemists tell us, is strained up to its last degree of endurance. The glistening bead of dew from which the daisy gently nurses its strength, and which a sunbeam may dissipate, is the globular compromise of antagonistic powers that would shake this building in their unchained rage. And so every atom of matter is the slave of imperious masters that never let it alone. It is nursed and caressed, next bandied about, and soon cuffed and kicked by its invisible overseers. Poor atoms! No abolition societies will ever free them from their bondage, no colonization movement waft them to any physical Liberia. For every particle of matter is bound by eternal fealty to some spiritual lords, to be pinched by one and squeezed by another and torn asunder by a third; now to be painted by this and now blistered by that; now tormented with heat and soon chilled with cold; hurried from the Arctic Circle to sweat at the Equator, and then sent on an errand to the Southern Pole; forced through transmigrations of fish, fowl and flesh; and, if in some corner of creation the poor thing finds leisure to die, searched out and whipped to life again and kept in its constant round.