It must here first be observed that the term "Conservation of Energy," is more correct and intelligible than "Conservation of Force"; by "Energy" being understood the power of doing "work," that is to say, of overcoming resistance.[35]
It is in this form alone that Force becomes subject to observation and can be measured by Science, and the Law of Conservation which observation[{24}] reveals is thus stated: The sum of all the various energies in the universe is a constant quantity, which can be neither increased nor diminished, though it may be changed from one form to another;[36] such forms being motion, heat, chemical action, electricity, magnetism.
But another point is of far greater importance. The mode in which Professor Haeckel states this fundamental Law is altogether deceptive. He tells his readers only half the truth, and when the other half is told, not only is his whole doctrine found to receive no support from the Laws of Energy, but it is these very Laws which appear most incompatible with it.
For, along with the Law of the Conservation, there is another, of the Dissipation of Energy. It is perfectly true, as Professor Haeckel often repeats, that the sum of Energy existing in the universe remains ever the same: but it is no less certain, as he unfortunately fails to remind his readers, that the stock of Energy available for the work of the universe is growing less every day. Though none is ever destroyed, much is constantly lost, being dissipated, or radiated into space, in the form of heat which can never be recaptured or translated into any form which can be of any practical avail. "It is lost for ever as far as we are concerned."[37]
From what we have heard concerning the Law of[{25}] Substance it might naturally be supposed that it certified us of the continued existence of the power required to carry on the operations of Nature, and that, accordingly, reason bids us to suppose these operations to be everlasting. But this neglected element of the reckoning, or Entropy as it is styled, leads scientific men to an entirely different estimate. Thus Professor Balfour Stewart writes:[38]
Although, therefore, in a strictly mechanical sense, there is a conservation of energy, yet, as regards usefulness or fitness for living beings, the energy of the universe is in process of deterioration. Universally diffused heat forms what we may call the great waste-heap of the universe, and this is growing larger year by year.
We have [he continues] regarded the universe, not as a collection of matter, but rather as an energetic agent—in fact, as a lamp. Now it has been well pointed out by Thomson,[39] that looked at in this light, the universe is a system that had a beginning and must have an end; for a process of degradation cannot be eternal. If we could view the universe as a candle not lit, then it is perhaps conceivable to regard it as having been always in existence; but if we regard it rather as a candle that has been lit, we become absolutely certain that it cannot have been burning from eternity, and that a time will come when it will cease to burn. We are led to look to a beginning in which the particles of matter were in a diffuse chaotic state, but endowed with the power of gravitation, and we are led to look to an[{26}] end in which the whole universe will be one equally heated inert mass, from which everything like life or motion or beauty will have utterly gone away.
It is doubtless true that attempts have been made to show that this conclusion is not final, and that there may be resources whereby Nature is able to recoup herself, and to draw upon some bank unknown to us for her missing store. As we have seen, Professor Haeckel simply takes for granted that some such means of recuperation exist and operate, and he is not wholly without countenance from others. Thus, no less an authority than Sir William Crookes addressing the Chemical Society as its president, thus expressed himself:[40]
If we may hazard any conjectures ... we may I think premise that the heat radiations propagated outwards, ... by some process of nature unknown to us, are transformed at the confines of the universe into the primary—the essential—motion of chemical atoms, which the instant they are formed, gravitate inwards, and thus restore to the universe the energy which would be lost to it through radiant heat. Hence Sir William Thomson's startling prediction falls to the ground.
But it need not be pointed out that if an advocate so eminent as Sir William Crookes is reduced to pleas like this on its behalf, the case for Renovation of Energy must be singularly destitute of anything resembling scientific support. Suppositions which[{27}] are avowedly hazarded as conjectures, and which must appeal to processes of Nature of which we know nothing, whatever authorship they may boast, have nothing to do with Science, and possess no sort of value for our purpose.[41] It must of course be allowed that we may still be utterly in the dark as to the whole of this question, and that further discoveries may one day completely upset all our present notions. But we are concerned with the evidence which Science has now before her, and with the assertion so confidently advanced that this makes the Law of ceaseless Evolution an indisputable truth. We find, on the contrary, that this Law runs directly counter to the facts as they are at present known to us, and to the conclusions drawn from them by the most authoritative representatives of science.