This, in fact, is the first proposition which we must all accept. No human being can add to or subtract a single property of any species of matter. To do so were, indeed, to create. For matter is an aggregate of properties; each species of matter is differentiated only by its properties, and could we alter one of these we should really turn it into different matter. It is true there are what are called allotropic forms, such as oxygen and ozone, the yellow and red phosphorus, the forms of sulphur as modified by heat, and a considerable number of organic compounds, and we can by certain arrangements turn the one into the other. But when we ask what allotropism is, we find that it is itself one of the properties (however obscure to us) of the matter we deal with. Oxygen would not be oxygen, but something else, if it had not the inherent property of becoming ozone under certain conditions. Given these conditions, and there is nothing we can do which will prevent the change occurring. If, as chemists believe, allotropism depends on the different arrangement of the ultimate atoms of matter, then the capacity of assuming two arrangements in its atoms is clearly one of the ultimate properties of that species of matter.
It follows, then, that if a miracle were really a suspension of a physical law, or a change, temporary or permanent, of any property of matter, it would really be an act of creation—the creation of something having different properties from any matter that before existed. If iron were to float on water by suspension of the law of gravity, it would be in fact the creation of something having (at least for the time required) the physical and chemical properties of iron, but with a specific gravity less than water—and therefore something not iron.
But, without creation, man has enormous power over Nature. He can, and daily does, overpower her laws, or seemingly make them work as he pleases. Despite the law of gravity, he ascends to the sky in a balloon; he makes water spring up in fountains; he makes vessels, weighing thousands of tons, float on the seas. Despite cohesion, he grinds rocks to powder; despite chemical affinity, he transmutes into myriads of different forms the few elements of which all matter consists; despite the resistless power of the thunderbolt, he tames electricity to be his servant or his harmless toy. With water and fire he moulds into shape mighty masses of metal; he shoots, at a sustained speed beyond that of birds, across valleys and through mountain ranges; he unites seas which continents had separated; there is nothing in the whole earth which he has not subdued, or does not hope to subdue, to his use. There is hardly a physical miracle which he does not feel he can, or may yet, perform.
But all this wonderful, this boundless, power over material laws is gained by these laws. He alters no property of matter, but he uses one property or another as he needs, and he uses one property to overpower another. It is by knowing that gravity is more powerful in the case of air than in the case of hydrogen gas, that he makes air sustain him as he floats, beneath a bag of hydrogen, above the earth; it is by knowing that it is more powerful in water than in air that he sails in iron ships; it is by knowing chemical affinity or repulsion that he makes the compounds or extracts the simple elements he desires; it is by knowing that affinity is force, and that force is transmutable into electricity, that he makes a messenger of the obedient lightning shock; it is by knowing that heat, itself unknown, causes gases to expand, that he makes machines of senseless iron do the work of intelligent giants. He subdues Nature by understanding Nature. He creates no property; he therefore performs no miracle, though he does marvels.
By what means, then, does man bring one property, or law, into play instead of, or against, another? By one means only, that of changing the position of matter.
This is Bacon's aphorism (Nov. Org. Book i. 4): "Man contributes nothing to operations except the applying or withdrawing of natural bodies: Nature, internally, performs the rest."
In order to trace and recognize the truth of this fact, let us follow in rough and rapid outline the operations by which man effects his purposes. We will begin at the beginning, and suppose him to have only reached the stage when a knowledge of the effects of fire enables him to work with metals. He produces fire by friction—that is, by bringing one piece of wood to another, and rapidly moving the one on the other; or else by striking two flints on each other, which also is merely rapid motion and shock. He carries the wood to a hearth, he brings to it the lump of crude metal or the ore; he urges the fire by a blast of air—still his acts are only those of imparting motion. Then the fire acts on the metal, it excites some affinities and enfeebles other affinities, which result in removing impurities; it softens the purified metal. Then the workman lifts it on a stone, and by beating it with another stone—still motion—he moves its particles so that it assumes the form of a hammer, an axe, a chisel, or a file. Then by rubbing with a rough stone—still motion—he moves away some particles from the edge, and makes it sharp and fit for cutting. By plunging it in water when hot—still only motion—he tempers it to hardness. With the edge thus obtained he cuts wood into the forms he requires for various purposes, and by degrees he learns how to fashion other pieces of metal into other and more elaborate tools. Yet all this is done by no other means than giving motion to the material on which, or by which, he works. From tools he advances to machines, by which his power of giving motion is increased, and as he learns more of the properties of matter he constructs engines, by which these properties work for him in the directions in which he guides them. Meantime he has learned that clay, when heated, becomes hard as stone, and the arts of pottery take their rise; while glass-making follows on the discovery that ashes and sand fuse into a transparent mass. Yet, whether in their rude beginning or finished elegance, man in these arts does no more than bring together the rough materials and apply to them heat, then their own inherent properties effect the result. Science—that is, knowledge of natural laws of matter—guides his hand, but his hand only moves matter; it gives no property and takes away none; it does not even enable one property to work; it does absolutely nothing except to place matter where its own laws work, to bring or to remove matter which is needed, or to remove matter which is superfluous. Let us analyze every complicated triumph of human knowledge and skill, and we shall find it all reduced to the knowledge of what the properties of matter are, and the skill which imparts to it motion just sufficient to permit these properties to operate. Man's power over Nature is therefore limited to the power of giving motion to matter, or of stopping or resisting motion in matter.
Now, to give motion or to resist motion is itself either a breach or a use of a law of Nature, according as we express that law. The law is (as usually expressed), that matter at rest remains at rest till moved by a force, and that matter in motion continues in motion till stayed by a force. This is the law of inertia. If we consider that rest or motion when once established is the normal state of matter, then the force which causes a change causes a breach of the law of inertia. But if we consider that the liability to be moved, or to have motion stopped by force, is itself a property of matter, then the application of force with such result is merely calling into operation the law of inertia. It really does not signify which view we take, so long as we recognize that such are the facts. But since it is more familiar to associate rest with inertia, it will perhaps be most convenient and simple to consider rest and motion as the laws of matter, till the law is interfered with. Therefore in what follows we shall say, that when matter at rest is moved, or when matter in motion is stayed, or its movement by a natural force is prevented, a breach of the law of inertia is committed.
We come, then, to these propositions:—1st, That human power is utterly unable to break any law of matter except the law of inertia. 2nd, That when, by breaking only the law of inertia—i.e., by moving or by resisting the motion of matter—any operation is accomplished, no other law of matter is broken. 3rd, That to break the law of inertia by Force, directed by Will, is no interference with the properties of matter. 4th, That by breaking the law of inertia only, man has power to call into play properties which make matter subservient to his objects.
Nor is this man's power only. Inferior animals can also move matter, and by moving it can cause prodigious results. A minute insect, by secreting lime from sea waters, makes a coral reef, or aids in forming a cliff of chalk. A beaver cuts down a tree, and forms a swamp that changes the climate of a district; a bird carries a seed, and makes a forest on an island. Inanimate life has the same power. The plant opens its leaves to the sun, and abstracts the carbon that forms fruitful soils and beds of coal. Matter itself can by motion work on matter. The great physical powers, heat and electricity, are modes of motion. Radiation of heat causes freezing, and freezing crumbles rocks into soil, or it forms the clouds in the air, whose deluges hollow valleys; while electricity cleaves and splinters the summits of the mountain peaks. Everywhere motion, sharp or slow, works with matter; everywhere the law of inertia is broken; and everywhere the miracles of Nature are wrought out by Nature's unbroken laws, set in action or withheld by only the movement which matter has received, be it from Will in man or beast, or be it from forces which themselves are part of matter's properties.