any supernatural deity. In this sense Schopenhauer justly remarks:

"'Pantheism is only a polite form of atheism. The truth of pantheism lies in its destruction of the dualist antithesis of God and the world, in its recognition that the world exists in virtue of its own inherent forces. The maxim of the pantheist, 'God and the world are one,' is merely a polite way of giving the Lord God his congé'" (p. 103).

Thus we are led on, from what may be supposed to be a bare statement of two recent generalisations of science,—first of all to regard them as almost axiomatic or self-evident; next, to consider that they solve the main problem of the universe; and, lastly, that they suffice to replace the Deity Himself.

To curb these extravagant pretensions it is only necessary to consider soberly what these physical laws really assert.

Conservation of Energy.

Take first the conservation of energy. This generalisation asserts that in every complete material system, subject to any kind of internal activity, the total energy of the system does not change, but is subject merely to transference and transformation, and can only be increased or diminished by passing fresh energy in or out through the walls of the system. So far from this being self-evident, it required very careful measurement and experimental proof to demonstrate the fact, for in common experience the energy of a system left to itself continually to all appearance diminishes; yet it has been skilfully proved that when the heat and every other kind of product is collected and measured, the result can be so expressed as to show a total constancy, appertaining to a certain specially devised function called "energy," provided we know and are able to account for every form into which the said energy can be transformed by the activity going on. A very important generalisation truly, and one which has so seized hold of the mind of the physicist that if in any actual example a disappearance or a generation of energy were found, he would at once conclude either that he had overlooked some known form and thereby committed an error, or that some unknown form was present which he had not allowed for: thereby getting a clue which, if followed up, he would hope might result in a discovery.

But the term "energy" itself, as used in definite sense by the physicist, rather involves a modern idea and is itself a generalisation. Things as distinct from each other as light, heat, sound, rotation, vibration, elastic strain, gravitative separation, electric currents, and chemical affinity, have all to be generalised under the same heading, in order to make the law true. Until "heat" was included in the list of energies, the statement could not be made; and, a short time ago, it was sometimes discussed whether "life" should or should not be included in the category of energy. I should give the answer decidedly No, but some might be inclined to say Yes; and this is sufficient as an example to show that the categories of energy are not necessarily exhausted; that new forms may be discovered; and that if new forms exist, until they are discovered, the law of conservation of energy as now stated may in some cases be strictly untrue; just as it would be untrue, though partially and usefully true, in the theory of machines, if heat were unknown or ignored. To jump, therefore, from a generalisation such as this, and to say, as Professor Haeckel does on page 5, that the following cosmological theorems have already been "amply demonstrated," is to leap across a considerable chasm:—

Most of this, though in itself probable enough, must, when scientifically regarded, be rated as guess-work, being an overpressing of known fact into an exaggerated and over-comprehensive form of statement. Let it be understood that I am not objecting to his speculations, but only pointing out that they are speculations.

The conservation of energy is a legitimate enough generalisation: we do not really doubt its conservation and constancy when we admit that we are not yet sure of having fully and finally exhausted the whole category of energy. What we do grant is, that it may hereafter be possible to discover new forms; and when new forms are discovered, then either the definition may have to be modified, or else the detailed statement at present found sufficient will have to be overhauled. But after all, this is not specially important: the serious mistake which people are apt to make concerning this law of energy is to imagine that it denies the possibility of guidance, control, or directing agency, whereas really it has nothing to say on these topics; it relates to amount alone. Philosophers have been far too apt to jump to the conclusion that because energy is constant, therefore no guidance is possible, so that all psychological or other interference is precluded. Physicists, however, know better; though unfortunately Tyndall, in some papers on Miracles and Prayer, thoughtlessly adduced the conservation of energy as decisive. This question of "guidance" is one of great interest, and I emphasise the subject further on, especially in Chapter IX.

Conservation of Matter.

Take next the "conservation of matter"—which means that in any operation, mechanical, physical, or chemical, to which matter can be subjected, its amount, as measured by weight, remains unchanged; so that the only way to increase or diminish the weight of substance inside a given enclosure, or geometrically closed boundary, is to pass matter in or out through the walls.

This law has been called the sheet-anchor of chemistry, but it is very far from being self-evident; and its statement involves the finding of a property of matter which experimentally shall remain unchanged, although nearly every other property is modified. To superficial observation nothing is easier than to destroy matter. When liquid—when dew, for instance—evaporates, it seems to disappear, and when a manuscript is burnt it is certainly destroyed: but it turns out that there is something which may be called the vapour of water, or the "matter" of the letter, which still persists, though it has taken rarer form and become unrecognisable. Ultimately, in order to express the persistence of the permanent abstraction called "matter" clearly, it is necessary to speak of the "ultimate atoms" of which it is composed, and to say that though these may enter into various combinations, and thereby display many outward forms, yet that they themselves are immutable and indestructible, constant in number and quality and form, not subject to any law of evolution; in other words, totally unaffected by time.

If we ask for the evidence on which this generalisation is founded, we have to appeal to various delicate weighings, conducted chiefly by chemists for practical purposes, and very few of them really directed to ascertain whether the law is true or not. A few such direct experiments are now, indeed, being conducted with the hope of finding that the law is not completely true; in other words, with the hope of finding that the weight of a body does depend slightly on its state of aggregation or on some other physical property. The question has even been raised whether the weight of a crystal is altogether independent of its aspect: the direction of its plane of cleavage with