Belief in substance, I have seen, is inevitable. The hungry dog must believe that the bone before him is a substance, not an essence; and when he is snapping at it or gnawing it, that belief rises into conviction, and he would be a very dishonest dog if, at that moment, he denied it. For me, too, while I am alive, it would be dishonest to deny the belief in substance; and not merely dishonest, but foolish: because if I am observant, observation will bring me strong corroborative evidence for that belief. Observation itself, of course, assumes a belief in discourse and in experience; it assumes that I can recognise essences, remembering their former apparitions and contexts and comparing the earlier with the present instance of them, or with the different essences which now appear instead. When I survey my experience in this way, the order of appearances, as memory or presumption sets it before me, will confirm the suasion which these appearances exercised singly, and will show me how very well grounded was the instinct which told me, when I saw some casual essence, that it was a sign of something happening in an independent, persisting, self-evolving, indefinitely vast world. If experience, undergone, imposes belief in substance, experience studied imposes belief in nature.

The word nature is sometimes written with a capital, as if nature were some sort of deity or person: and in ancient philosophy and common speech, powers and habits are attributed to nature which imply a certain moral idiosyncrasy in that personage. Poets also praise nature, and theologians rehearse her marvellous ways, in order to show that she could not have fallen into them of her own accord. All this mythology about nature is natural, and perhaps shows a better total appreciation of what nature is than would a precise physics. The precision of physics is mathematical; it defines an essence; and the attribution of this mathematical essence to nature, however legitimate, is sure to overlook many properties which belong to her just as truly, and appear in the realms of truth or of spirit. One such property, at least, is fundamental, and is better expressed by personifying nature than by describing her movements mathematically, I mean, her constancy, the assumption that we may trust her to be true to herself. In science, some observed or some hypothetical process is studied and the method or law of it is ascertained: but there is nothing particularly scientific in the presumption that this process is all that is going on in the given case, or that it will recur in other cases. What is called the uniformity of nature is an assumption made, in respect to the future, without any evidence, and with proportionately scanty evidence about the past: where experience confirms it in some particular, the confirmation itself is good for those instances, up to that time: it tells me nothing of anything beyond, or of the future. The source of my confidence is animal faith, the same that inspires confidence in a child towards his parents, or towards pet animals; and the whole monstrous growth of human religion is an extension of this sense that nature is a person, or a set of persons, with constant but malleable characters. As experience remodels my impulses, I assume that the world will remain amenable to my new ways; the convert feels he is saved; the philosopher thinks he has found the key to happiness; the astronomer tells you he has measured the infinite, and perhaps rolled it up upon itself, and put it in his pocket. They all express the infantile conviction that nature cannot be false to what they have already learned or instinctively affirmed of it: making nature a single and quasi-personal entity, bound tragically to its past, and pledged more or less wilfully to a particular future. It is this sense that the world, like a person, has a certain vital unity, and remains constant or at least consequential in its moral aspects, that is expressed by calling it nature. Like a being born of a seed, it has a determinate form, and a normal career, a nature, which it cannot change.

What evidence is there for the existence of nature, in this sense of the word? If I speak of the universe at large, there can be no evidence. Of course the universe must be what it is, it must have a character, it must exemplify an essence; but taken as a whole, it may be a chaos, in which nothing is predeterminate, nor progressive, nor persistent, and in which the parts are self-centred and the events spontaneous. A philosopher who took his own life as a model for conceiving all other things, ought perhaps to incline to this view; because he is himself, transcendentally speaking, an absolute centre, and being ignorant of the sources of his thoughts and actions, may presume that they have no sources. If under these circumstances he still has the weakness (for it would be a weakness) to believe in anything else, say in other monads, he would doubtless allow them an equal liberty; so that in his universe of monads there would be no common space, no common time, no common type of character or development, no mutual influence or kindred destiny. I think the inner life of animals, if we treated each as a moral romance, apart from its physical setting and influence, would actually present such a chaos: especially if we imagine what may be the lives of creatures in other parts of the stellar universe, or out of any relation with ourselves at all. Such a loose universe could not properly be called nature. It would not have given us birth, it would not have nurtured us, it would not surround us with any constant influences or familiar aspects, it would not bring any seeds to maturity for our encouragement or warning.

Evidences for the existence of nature must be sought elsewhere, in a region which a monadologist would regard as internal to each monad, in that the substances posited by me in obedience to my vital instincts seem to me to behave as if they were parts of nature. Nature is the great counterpart of art. What I tuck under my pillow at night, I find there in the morning. Economy increases my possessions. People all grow old. Accidents have discoverable causes. There is a possible distinction between wisdom and folly. But how should all this be, and how could experience, or the shocks that punctuate it, teach me anything to the purpose, or lend me any assurance in life not merely a reinforced blindness and madness on my part, unless substances standing and moving in ordered ways surrounded me, and I was living in the midst of nature? Certainly a partial sceptic like Berkeley, closing one eye in the interests of a sentimental religion, may conceive that nature is not a system of evolving substances round him affecting his own growth, but a perpetual illusion, like a dream: a story told him in the dark, a consecutive miracle of grace or of punishment by which a divine spirit dazzles and conducts his spirit, without any medium or any occasion. But if this fairy-tale is to hold good, and to justify the arts of life and maintain the distinction between vice and virtue, I must be able to discern the ways of Providence in their routine; everything will happen exactly as if nature existed, and unrolled itself in a mechanical, inexorable, and often shocking way; my idealism will merely allow me to admit miracles, and to hope that to-morrow everything will be well. If I regard the world of appearance as a mask which the deity wears inevitably, the very essence of the creator being to create such a world, the difference between belief in God and belief in nature will be merely verbal, and I may say with Spinoza, Deus sive natura. If on the contrary God is approachable in himself and would prove a better companion than nature and sweeter to commune with, why should he terrify me or delude me with this unworthy disguise? Why should he have preferred to manifest himself by creating appearances rather than by creating substances? What secret necessity could have compelled him to create anything at all, or whispered in his ear these irresponsible designs? If nature behaves as nature would, is it not simply nature? If God were there instead would he not behave like God? Or if I say that I have no right to presume how God should behave, but that wisdom counsels me to learn his ways by experience, what difference remains between God and nature, and are they more than two names for the same thing?

If by calling nature God or the work of God, or the language in which God speaks to us, nothing is meant except that nature is wonderful, unfathomed, alive, the source of our being, the sanction of morality, and the dispenser of happiness and misery, there can be no objection to such alternative terms in the mouth of poets; but I think a philosopher should avoid the ambiguities which a too poetical term often comports. The word nature is poetical enough: it suggests sufficiently the generative and controlling function, the endless vitality and changeful order of the world in which I live.

Faith in nature restores in a comprehensive way that sense of the permanent which is dear to animal life. The world then becomes a home, and I can be a philosopher in it. Perhaps nature is not really constant, nor single; unless indeed I so stretch and eviscerate the notions of unity and constancy as to apply them to the total aspect of nature, under the form of eternity, however incoherent and loose the structure of that totality may be. But in this æon, in this portion or special plane of space, a sufficient constancy is discoverable: far greater than my scope can cover, or my interest require. It is inattention and prejudice in men, not inconstancy in nature, that keeps them so ignorant, and the art of government so chaotic. Whenever a little persistent study of nature is made (as recently in the interest of mechanical inventions) rapid progress at once follows in the arts: and art is the true discoverer, the unimpeachable witness to the reality of nature. The master of any art sees nature from the inside, and works with her, or she in him. Certainly he does not know how he operates, nor, at bottom, why he should: but no more does she. His mastery is a part of her innocence. It happens so, and within limits it prospers. To that extent he has assurance of power and of support. It is a faith congruous with his experience that if he could bend his faculties more accurately to their task, nature would prove indefinitely tractable: and if a given animal with special organs and a special form of imagination can progressively master the world, the fact proves that the world is con-natural with him. I do not mean that it favours his endeavours, much less that it is composed as his fancy pictures it; I mean only that his endeavours express one of the formations which nature has fallen into, for the time in equilibrium with the surrounding formations; and that his ideas too are in correspondence with the sphere of his motions, and express his real relations. The possibility of such correspondence and such equilibrium proves that nature exists, and that the creature that sustains them is a part of nature.