what is external and what is not, a difficulty upon which the whole materialistic hypothesis is suspended.

Not to prolong this debate too far, I suppose it has been demonstrated by analysis and argument, that what is external in matter is all that we conceive can exist in the absence of the sensitive subject, for instance, extension, motion, impenetrability. Here the difficulties cease to be psychologic; they become metaphysical. I will mark but two of the highest importance: infinite divisibility and the coexistence of force and extension. Mr. Büchner, abandoning on this point the materialistic tradition, renounces the atomic hypothesis and admits the infinite divisibility of matter, but thereby, it seems to me, lets go whatever is positive and clear in the conception of matter. Through the infinite divisibility of matter, it vanishes and disperses, without our being able for a moment to seize and retain its image. Imagine a compound; for instance, a heap of sand: what is there real in this object? Plainly the grains of sand of which it is composed, for the compound itself is something only to the mind it is only the sum of the parts; if there were no parts it would not exist. We may therefore say in strictness that a compound has no reality save that which it owes to its integral particles: it is a form which is nothing without the matter to which it applies. The sand heap having no reality, save that it owes to the sand grains which compose it, let us now suppose the grain of sand itself to be a compound: this sand grain, like the heap itself, will only have a provisional and relative reality, subordinated to the reality of its constituent particles. Suppose the same thing of the same parts: they themselves will not yet be the reality, and pushing this research to infinity, since there are no last terms, we shall never learn what constitutes the reality of matter. We will therefore say of matter in general, what we say of each particular compound, that it is only a provisional and relative thing, subordinated to some absolute condition to us unknown.

The same reasoning will apply to force as to matter, the two things being inseparable, according to Messrs. Moleschott and Büchner. If matter is infinitely divisible, equally so is force; but we shall say, as before, that a compound force has no reality other than that of its component forces. The force of a twohorse team is only the sum of the two forces inherent in those

horses. In reality, what exists is not the resultant which the mathematician considers, but two distinct, associated forces. If this is so, the general force spread through a heap of matter must be reduced to the elementary forces inherent in the particles of the whole; but if these particles are themselves compounds, the forces belonging to them are no less so, and consequently are not as yet the forces we seek. Finally, if all force is infinitely divisible, we shall never find the last force, that atom of force without which compound force is nothing real. Thus force vanishes like matter.

Strive now to conceive of this divisible infinite (matter and force) as an absolute, self-subsisting; you will not succeed. What is there, what can there be absolute in a compound? Obviously the elements, for no one will say, for example, that this tree, this stone, possesses absolute existence. These things are only accidental forms produced by the encounter of elements. The whole itself, the cosmos, is but the form of forms, the sum of all anterior forms. The absolute necessity of matter can then only reside in the elements of matter, and there materialists have always placed it. But if there are no elements, where then resides absolute necessity? And how could matter be conceived as self-existent ?

Thus the infinite divisibility of matter, if it was allowed as true, would bring the German school to admit some principles different from matter, which, giving consistency to this absolute fluidity, should permit it to exist. In a word, a more profound study would bring back the new school from materialism to idealism.

This is not all. Messrs. Moleschott and Büchner have set forth, as a self-evident principle, the necessary coexistence of matter and force; but if from bodies you abstract force, from what now do motion and impenetrability arise, what remains to constitute matter? Nothing but extension. Matter is then an extended thing endowed with force. This extended thing moves, that is, changes its place in space: it is then distinct from the space which contains it. Now exactly here materialism has ever been greatly embarrassed, for how shall we distinguish this extended particle from the corresponding particle of space which it fills? Imagination, assuming here the place of the understanding, represents to us a kind of dustlike grains

floating in the air. So the Epicurean atoms floated in the void. But begin by stripping this dustlike grain of all that sight and the other senses make known concerning it, reduce it to extension and force, do not forget that force is a property of matter and consequently of extension, and say to yourself that this atom, considered in itself, is nothing but a portion of extension. It has, then, no mark by which it can be distinguished from the corresponding portion of space which it is thought to inhabit. Do not say that it is distinguished by the force which animates it, for then it would be force which would constitute matter; matter would be lost in force, which is the opposite of your system and the giving up of the materialistic principle. If, on the contrary, you admit a matter essentially extended, you will confound it, like Descartes, with space, and then try to conceive motion, figure, diversity, in this space infinite, homogeneous, and full.

But such a discussion is of too abstract and delicate a nature to be long continued. I have said enough to prove that the new German materialism has shown from the start ignorance enough of discussion in setting up as a principle the coexistence of force and matter, without giving any definition of either, and without showing what bonds unite them. The demonstrated insufficiency of the principle appears in all the consequences which can be drawn from it. Two examples will suffice for proof: they are the ideas of materialists upon the principle of life, and the principle of thought.

IV.

One of the most obscure problems of human science, before which a circumspect philosophy will ever prefer maintaining silence to proposing hypotheses so difficult to verify, is the problem of the origin of life upon the terrestrial globe. If there is a demonstrated truth in geology, it is that life has not always existed in the world, and that it has appeared here on a given day, doubtless under its most elementary form, for everything inclines us to believe that nature in her development follows the law of gradation and progress; but at length, on a given day, life appeared. How? Whence came it? By what miracle did inert matter become living and animated?

That, I repeat, is a great mystery, and every sage will prefer silence to affirmation of he knows not what.

To Mr. Büchner there is no difficulty. Life is a certain combination of matter, which became possible the day when it first encountered favorable circumstances. If he limited himself to these terms it would be hard to refute him, for who can know what is possible and what is not. But the German author goes much further. According to him, nature has never seen the appearance of a new force. All that was produced in the past must have been produced by forces similar to those which, to-day, we perceive. Thereby he pledges himself to maintain that to-day even, we witness the miracle of the origin of life, that matter is fitted to spontaneously produce living organisms. Bringing the question upon this ground, he furnishes a solid basis for discussion, for we can then ask what science teaches us about the actual origin of living beings; in a word, what is to-day the position of science upon the old and celebrated question of spontaneous generation.

By spontaneous generation, or heterogeny, is meant the formation of certain living beings, without preexisting germs, by the sole play of the physical and chemical forces of matter. From the highest antiquity, people have believed in spontaneous generation. "We see" (says Lucretius) "worms all alive start from fetid clay, when the earth, softened by rain, has gained a sufficient degree of putrefaction. The elements set in motion, and brought together in new conditions, give birth to animals." This belief lasted even to the sixteenth and seventeenth century. Von Helmont describes the method of producing mice, frogs, and eels. A decisive experiment of Redi gave a deadly blow to all these ridiculous superstitions. He showed that the worms which come from meat are the larvæ of flies' eggs, that, by enveloping the meat with a light varnish, the birth of these larva may be prevented; still later, the eggs were detected and the mystery was explained. However, the discovery of the microscope opened a new path to the partisans of spontaneous generation. The microscopic animals which appear in infusions of animal and vegetable matter seemed to be produced apart from sexual conditions and without preexisting germs. The fine experiments of Needham seemed to decide in favor of this opinion; those of Spallanzani made it give

way, without overcoming it decisively. In the beginning of the present century, the capital experiment of Schwann gave the finishing stroke to the question, against spontaneous generation. Science seemed to have abandoned this question, when Mr. Pouchet brought it into fashion again, by experiments which made a stir, and which, to his mind, were decisive for generation without germs. The antivitalists were still rejoicing, when another savan, one of our most eminent chemists, Mr. Pasteur, took up the question, and carried it nearly as far as we can to-day go by the most delicate, ingenious, and solid experiments, he has refuted all the arguments of the heterogenists, and I believe we can say that, in this great debate, the Academy of Sciences and the great majority of savans think him right.

It would be difficult here to enter into the details of the experimental discussions that have taken place. Let us be content to give a general and philosophical idea of the question. It is now a remarkable fact, a presumption unfavorable to spontaneous generation, that the partisans of this theory have been gradually crowded back into the domain of the infinitely small, into the sphere of the invisible, so to say, where experiments are so difficult and the eye is so easily deceived. If such a mode of generation were possible, we do not see why it should not take place in other departments of animal life, and why it should be precisely reduced to the microscopic world.

Mr. Büchner says, to be sure, that those are the most imperfect organisms, and that consequently it is thought that they may be produced by the simplest and most elementary mode of generation; but it is still to be demanded whether the perfection of organisms bears a direct ratio to their dimensions, and whether the smallest are always the most imperfect. Now this is certainly not true. If we admit, with Mr. Milne Edwards, that the perfection of the animal is in proportion to what he calls the division of labor, that is, the division of organs and functions, it is easy to see that this division is wholly independent of the stature of the animal. Thus insects, for example, though generally very small, are very superior as animals to molluscs, in the number and division of functions, and yet greatly their inferiors in dimensions. Man, the most perfect of animals, is not the largest. We cannot, therefore,