The fact that we modify our opinions suggests that our ideas are formed not so much in involuntary self-adjusting mimetic correspondence with the objects that we believe to give rise to them, as by what was in the outset voluntary, conventional arrangement in whatever way we found convenient, of sensation and perception-symbols, which had nothing whatever to do with the objects, and were simply caught hold of as the only things we could grasp. It would seem as if, in the first instance, we must have arbitrarily attached some one of the few and vague sensations which we could alone at first command, to certain motions of outside things as echoed by our brain, and used them to think and feel the things with, so as to docket them, and recognise them with greater force, certainty, and clearness—much as we use words to help us to docket and grasp our feelings and thoughts, or written characters to help us to docket and grasp our words.

If this view be taken we stand in much the same attitude towards our feelings as a dog may be supposed to do towards our own reading and writing. The dog may be supposed to marvel at the wonderful instinctive faculty by which we can tell the price of the different railway stocks merely by looking at a sheet of paper; he supposes this power to be a part of our nature, to have come of itself by luck and not by cunning, but a little reflection will show that feeling is not more likely to have “come by nature” than reading and writing are. Feeling is in all probability the result of the same kind of slow laborious development as that which has attended our more recent arts and our bodily organs; its development must be supposed to have followed the same lines as that of our other arts, and indeed of the body itself, which is the ars artium—for growth of mind is throughout coincident with growth of organic resources, and organic resources grow with growing mind.

Feeling is the art the possession of which differentiates the civilised organic world from that of brute inorganic matter, but still it is an art; it is the outcome of a mind that is common both to organic and inorganic, and which the organic has alone cultivated. It is not a part of mind itself; it is no more this than language and writing are parts of thought. The organic world can alone feel, just as man can alone speak; but as speech is only the development of powers the germs of which are possessed by the lower animals, so feeling is only a sign of the employment and development of powers the germs of which exist in inorganic substances. It has all the characteristics of an art, and though it must probably rank as the oldest of those arts that are peculiar to the organic world, it is one which is still in process of development. None of us, indeed, can feel well on more than a very few subjects, and many can hardly feel at all.

But, however this may be, our sensations and perceptions of material phenomena are attendant on the excitation of certain motions in the anterior parts of the brain. Whenever certain motions are excited in this substance, certain sensations and ideas of resistance, extension, &c., are either concomitant, or ensue within a period too brief for our cognisance. It is these sensations and ideas that we directly cognise, and it is to them that we have attached the idea of the particular kind of matter we happen to be thinking of. As this idea is not like the thing itself, so neither is it like the motions in our brain on which it is attendant. It is no more like these than, say, a stone is like the individual characters, written or spoken, that form the word “stone,” or than these last are, in sound, like the word “stone” itself, whereby the idea of a stone is so immediately and vividly presented to us. True, this does not involve that our idea shall not resemble the object that gave rise to it, any more than the fact that a looking-glass bears no resemblance to the things reflected in it involves that the reflection shall not resemble the things reflected; the shifting nature, however, of our ideas and conceptions is enough to show that they must be symbolical, and conditioned by changes going on within ourselves as much as by those outside us; and if, going behind the ideas which suffice for daily use, we extend our inquiries in the direction of the reality underlying our conception, we find reason to think that the brain-motions which attend our conception correspond with exciting motions in the object that occasions it, and that these, rather than anything resembling our conception itself, should be regarded as the reality.

This leads to a third matter, on which I can only touch with extreme brevity.

Different modes of motion have long been known as the causes of our different colour perceptions, or at any rate as associated therewith, and of late years, more especially since the promulgation of Newlands’ [260a] law, it has been perceived that what we call the kinds or properties of matter are not less conditioned by motion than colour is. The substance or essence of unconditioned matter, as apart from the relations between its various states (which we believe to be its various conditions of motion) must remain for ever unknown to us, for it is only the relations between the conditions of the underlying substance that we cognise at all, and where there are no conditions, there is nothing for us to seize, compare, and, hence, cognise; unconditioned matter must, therefore, be as inconceivable by us as unmattered condition; [261a] but though we can know nothing about matter as apart from its conditions or states, opinion has been for some time tending towards the belief that what we call the different states, or kinds, of matter are only our ways of mentally characterising and docketing our estimates of the different kinds of motion going on in this otherwise uncognisable substratum.

Our conception, then, concerning the nature of any matter depends solely upon its kind and degree of unrest, that is to say, on the characteristics of the vibrations that are going on within it. The exterior object vibrating in a certain way imparts some of its vibrations to our brain—but if the state of the thing itself depends upon its vibrations, it must be considered as to all intents and purposes the vibrations themselves—plus, of course, the underlying substance that is vibrating. If, for example, a pat of butter is a portion of the unknowable underlying substance in such-and-such a state of molecular disturbance, and it is only by alteration of the disturbance that the substance can be altered—the disturbance of the substance is practically equivalent to the substance: a pat of butter is such-and-such a disturbance of the unknowable underlying substance, and such-and-such a disturbance of the underlying substance is a pat of butter. In communicating its vibrations, therefore, to our brain a substance does actually communicate what is, as far as we are concerned, a portion of itself. Our perception of a thing and its attendant feeling are symbols attaching to an introduction within our brain of a feeble state of the thing itself. Our recollection of it is occasioned by a feeble continuance of this feeble state in our brains, becoming less feeble through the accession of fresh but similar vibrations from without. The molecular vibrations which make the thing an idea of which is conveyed to our minds, put within our brain a little feeble emanation from the thing itself—if we come within their reach. This being once put there, will remain as it were dust, till dusted out, or till it decay, or till it receive accession of new vibrations.

The vibrations from a pat of butter do, then, actually put butter into a man’s head. This is one of the commonest of expressions, and would hardly be so common if it were not felt to have some foundation in fact. At first the man does not know what feeling or complex of feelings to employ so as to docket the vibrations, any more than he knows what word to employ so as to docket the feelings, or with what written characters to docket his word; but he gets over this, and henceforward the vibrations of the exterior object (that is to say, the thing) never set up their characteristic disturbances, or, in other words, never come into his head, without the associated feeling presenting itself as readily as word and characters present themselves, on the presence of the feeling. The more butter a man sees and handles, the more he gets butter on the brain—till, though he can never get anything like enough to be strictly called butter, it only requires the slightest molecular disturbance with characteristics like those of butter to bring up a vivid and highly sympathetic idea of butter in the man’s mind.

If this view is adopted, our memory of a thing is our retention within the brain of a small leaven of the actual thing itself, or of what quâ us is the thing that is remembered, and the ease with which habitual actions come to be performed is due to the power of the vibrations having been increased and modified by continual accession from without till they modify the molecular disturbances of the nervous system, and therefore its material substance, which we have already settled to be only our way of docketing molecular disturbances. The same vibrations, therefore, form the substance remembered, introduce an infinitesimal dose of it within the brain, modify the substance remembering, and, in the course of time, create and further modify the mechanism of both the sensory and motor nerves. Thought and thing are one.

I commend these two last speculations to the reader’s charitable consideration, as feeling that I am here travelling beyond the ground on which I can safely venture; nevertheless, as it may be some time before I have another opportunity of coming before the public, I have thought it, on the whole, better not to omit them, but to give them thus provisionally. I believe they are both substantially true, but am by no means sure that I have expressed them either clearly or accurately; I cannot, however, further delay the issue of my book.