We make a gun, load it, and discharge a bullet against a target. What has become of the force expended? It has been transformed into heat, say the conservationists. And when the target and flattened bullet have cooled down? The energy has gone to raise the general temperature of the universe!

That is a conclusion hard to believe and impossible to verify. But—granting that the individual explosions of a gun may be the 'conservation' of some antecedent power—how do we recover the initial expense of the instrument? And if not recoverable, where at least and in what form does it exist? Prior to the explosions that are represented by heated targets and the like, energy was spent in inventing and making the gun, making the ammunition, loading and aiming the piece. All these were essential to the effect—and what has become of them? Have they also gone to warm the universe?

Instead of raising a stone to a height, let us carry it along horizontally till we feel the same degree of fatigue. If energy in the using is merely transformed but not lost, we should now be in possession of some power equivalent to the energy expended. But we are not—we have nothing to show for our trouble.

If we construct a water-mill and fix it high and dry in the middle of a plain, instead of under a fall of water, we get no return for the energy expended. By such a law as the conservation of energy, and with the usefulness of a properly placed mill as the measure of compensation, we should receive an equivalent return no matter where the mill is placed. What has place to do with the action of a universal law?

Instead of raising the stone or carrying it horizontally, let us find it near the edge of a precipice and roll it over. There is no proportion between the push that launched the stone, and the force it exhibits on reaching the foot of the precipice. How is the equivalence of energy maintained in this case? It will be replied that the force now at work is gravitation. If so, it was gravitation that brought down the first stone on the post—not any energy transferred from us to the stone. The raising of the stone put us in a position to use the force of gravity, just as climbing the precipice put us in a position to roll the stone over the edge of it.

Such considerations as these make this 'law' incredible to me. But when I pass from the explanation to the concrete facts, I have no difficulty in understanding them. It is the law that is obscure—not the facts.

There exists nothing but living minds of different degrees of energy. We men are small beings associated with a cosmical creature whose force is immeasurably greater than ours, and we have intelligence enough to utilise part of this force to supplement our own. That is the meaning of mechanism. Some efforts to control the cosmic forces are profitable, but there is no transmutation of our energy into the result, nor any necessary equivalence between the labour and the result. We may stumble upon an available cosmic force almost by accident—we may waste a life-time over a mechanical problem and fail to solve it.

The utilisation of cosmic force by man is best explained by comparing it with animal slavery. Trap a wild elephant and train him to draw and carry—you have constructed an engine. There are of course important differences between the two kinds of instrument, due to the enormous disproportion between the magnitude and power of the respective entities. In the case of the animal the whole life comes under our control: in the case of the cosmos we can utilise only a minute fraction of it, and that rather by putting ourselves in its way than by making it obey us. The animal we have to feed: the cosmic being does not draw upon us for its nourishment. We can direct the animal through his sensibility: the cosmic sensibility appears to be beyond our power of irritation.

Apart from these differences the general laws of the one kind of tool are those of the other also. We have not transferred power to the raised stone, or the coiled spring, or the loaded gun, or the embanked river—any more than to the tamed and harnessed horse. There is no fixed ratio between the fatigue of catching and training an animal, and the energy saved by making him work for us. The animal's work is not our own energy given back to us—neither is the machine's. A plough is useless without cattle to draw it—so is a turbine without water to drive it. When coal is burned to 'generate' electricity, that is the cosmic equivalent of exhausting or killing one animal to overpower or to feed another: the energy of combustion is utterly destroyed—not transformed into the electricity.

The question can be more accurately stated and brought to a plain issue if we use the terms and forms of dialectic.