That spirit or mind has a relation to space, is evident from the fact of its location in the body. The body itself exists in space, therefore every particle of substance which it contains must exist in space. No point can be assumed in the body but what has a relation to the surrounding space or extension. Therefore spirit must have a relation to extension or it cannot exist in the body. All unextended points have a relation to space, though they are no part of space, and do not occupy space; but an unextended substance to have no relation to space cannot be as much as a point. A point is a located nothing, but an unextended substance is nothing, having no location.

What can be more unphilosophical, contradictory, and absurd, than to assume that something can exist that is "unextended,"—that "occupies no room, fills no space,"—has "no parts?" We ask our readers to pause for a moment, and endeavour to conceive of a substance that has no parts. Grasp it if you can in your imaginations. Think of its existing where there is no space. Conceive, if you can in your imaginations. Think of its existing where there is no space. Conceive, if you can, of a locality outside of the bounds of a boundless space. Do not your judgments, and every power of your minds revolt at the absolute absurdities and palpable contradictions? By this time, perhaps, you are ready to inquire, can it be possible that any man in all the world could believe in such impossibilities? Yes, it is possible. These very absurdities now stand in bold relief, not only in the most approved philosophical works of modern times, but incorporated in the very "Articles of Religion" which millions have received as their rule of faith.

That spirit or mind has a relation to duration is manifest in the act of remembering. Through the memory the mind perceives itself to be the same conscious being now, that it was, an hour, a day, a year ago; it perceives that itself has existed through a certain period of duration. There is as much certainty of its own relations to duration as there is of any such relation in any other substance whatever. If there is no certainty that mind has a relation to duration, there is no certainty that any other substance has such a relation; hence all would be uncertainty, even our own existence. Bishop Berkeley denied the existence of the material world, and the first Article of his religion swept away the immaterial world from space; and the modern immaterialist sweeps it away from all relation to time. So between them all, space and time are pretty well cleaned out; not so much as a nest egg left to replenish the great infinite void.

Mind, like all other matter, is susceptible of being moved from place to place. We see this exemplified in the movements of the mind through the medium of the body which conveys it from place to place on the surface of the earth. But though man was stationary upon the earth's surface, the earth itself with all its inhabitants, is moving with the rapid velocity of nineteen miles every second, which proves to a demonstration that mind is capable of being moved from place to place with a velocity far exceeding that of a cannon ball. But motion involves the ideas of both space and time. Mind cannot be moved without being moved in space; it cannot pass from point to point instantaneously. However rapid the velocity, time is an essential ingredient to all motion. That eminent and profound philosopher, the late Professor Robison of Edinburgh, says, "In motion we observe the successive appearance of the thing moved in different parts of space. Therefore, in our idea of motion are involved the ideas or conceptions of space and time."

"All things are placed in space, in the order of situation. All events happen in time, in the order of succession."

"No motion can be conceived as instantaneous. For, since a moveable, in passing from the beginning to the end of its path, passes through the intermediate points; to suppose the motion along the most minute portion of the path instantaneous, is to suppose the moveable in every intervening point at the same instant. This is inconceivable and absurd." (Robison's Mechanical Philosophy. Vol I. Introduction.) The motion of mind, therefore is another positive proof that it has a relation to both space and duration.

"Extension and resistance," says Dr. Thomas Brown, "are the complex elements of what we term matter; and nothing is matter to our conception, or a body, to use the simpler synonymous term which does not involve these elements." Figure, magnitude, divisibility, are only different modifications of extension. Solidity, liquidity, viscidity, hardness, softness, roughness, smoothness, are different modifications of resistance. All these terms are only extension and resistance, modified in a certain degree, and under other names. Our notion of extension is supposed by Dr. Brown to be acquired from our notion of time as successive, involving length and divisibility. Our notion of resistance he supposes to be obtained through our muscular organs. These organs are first exerted, and then excited by something without, and in their turn excite the mind with a feeling of resistance. The feeling of resistance combined with the feeling of extension gives us the notion of matter. If Dr. Brown's views be correct, no one can acquire a notion of matter, by seeing, hearing, tasting, smelling, or simple touch. Either or all of these will only produce certain feelings in the mind without giving us any notion of an external extended resistance. A muscular effort opposed by some substance or foreign body is the only possible way, according to his theory, for the infant mind to obtain a notion of extended solidity or resistance. (Brown's Philosophy of the Human Mind. From the XX to the XXIX Lecture inclusive.)

If solidity and extension then are the essential characteristics of matter; and if the resistance of a muscular effort be the only possible way of learning these characteristics; it may be asked, how did Dr. Brown learn that the rays of light are material? He has frequently in his philosophy called light material. Has light in any way resisted his muscular efforts? Have the muscular organs ever been able to grasp a ray of light? Have the particles of light either singly or collectively ever acted upon our muscular organs in such manner as to give us a notion of extension and resistance? Have they ever affected the mind in any way only to impart to it the feeling of color? Does not Dr. Brown himself repeatedly affirm, that light can only impart the sensation of color; and that extension, magnitude, figure, solidity, can never be known by the sense of seeing? Does he not assert, that "nothing is matter to our conception which does not involve these elements?" Why then does he assume light to be material?

If, then, light can be ranked as a material substance without exhibiting the least resistance to the muscular organs, why not mind or spirit be considered material also? Why believe that light consists of inconceivably small vibratory or emanating particles of matter from the mere affection of mind called color, and yet be unwilling to believe that the mind affected is material? If that which produces a sensation or feeling be regarded a solid extended substance, independently of muscular resistance, where is the impropriety, in regarding that which receives the sensation or feeling, as a solid extended substance also?

Dr. Brown, and all other immaterialists, universally believe that the sensation of smell is produced by small material particles, acting upon our olfactory nerves. But we ask, how is Dr. Brown or any other person to determine those odorous particles to be material? It may be said, that we determine them to be solid and extended by tracing them to the substances from which they emanate. But can it be proved that they constitute any part of the solid extended substance from which they emanate, any more than light is a part of the substance from which it emanates? We know a rose to be solid and extended, not from the sensation of vision or smell, but from the sensation of resistance which it offers to our muscular organs when we attempt to grasp it. But because a rose is solid and extended, that does not prove that light and fragrance, by which we discern its color and smell, are any part of the rose.

If Dr. Brown's theory be true, it is absolutely impossible to prove that the odoriferous particles which affect us with the sensation of fragrance, are a solid extended substance. These particles of odour appear, indeed, to have been connected in some way with bodies from which they emanate; but there is no possible means for the muscular powers to determine them to be parts of those bodies, any more than the colored light or the heat which are also transmitted from them. No one in speaking of a rose would think of classifying heat and light as a portion of its solid substance; yet both heat and light, like the particles of odour, are intimately connected with it, and are constantly being thrown off from it.

"What is there," inquires Dr. Brown, "which we can discover in the mere sensation of fragrance, that is itself significant of solidity, extension, or whatever we may regard as essential to the existence of things without? As a mere change in the form of our being, it may suggest to us the necessity of some cause or antecedent of the change. But it is far from implying the necessity of a corporeal cause;—any more than such a direct corporeal cause is implied in any other modification of our being, intellectual or moral—in our belief, for example, of the most abstract truth, at which we may have arrived by a slow development of proposition after proposition in a process of internal reflective analysis, or in the most refined and sublime of our emotions, when, without thinking of any one of the objects around, we have been meditating on the divinity who formed them—himself the purest of spiritual existences. Our belief of a system of external things, then, does not, as far as we can judge from the nature of the feelings, arise from our sensations of smell, more than from any of our internal pleasures or pains." (Brown's Philosophy of the Human Mind. Lecture XX.)

Odorous particles, then, have never been submitted to Dr. Brown's only test of materiality, and yet he, and all other immaterialists, without any hesitation, pronounce them to be matter. The spirit, like these particles of odour, can exist in connexion with the body or separate from it; and yet it forms no part of the fleshy tabernacle. If like the particles of odour, it really eludes the grasp of the muscular organs, and if neither these odoriferous particles, nor the spirit, can be proved by any muscular effort to have solidity and extension; why, then, should one be called material, and the other immaterial?

If the mind be unextended, how can it receive any sensations from things without? It could not act upon bodily organs, for they are extended. Neither could bodily organs act upon it.

Philosophers have endeavoured to invent numberless hypothesis to account for the action of matter on the mind, which they have assumed to be immaterial. The old Peripatetic doctrine of perception, by species or phantasms, which for so many centuries held so unlimited a sway in the philosophic world, was probably originated to connect material with immaterial substances. When this absurdity slowly died away, other hypothesis, no less erroneous, immediately supplied its place. Des Cartes, seeing no possibility of any reciprocal action between matter and something that was inextended, invented his system of occasional causes, and represented the external world entirely incapable of affecting the mind in any way whatever. He ascribed all the sensations and affections of the mind to the immediate agency of the Deity, virtually rendering external objects entirely useless to the mind. This conjecture has been modified by succeeding philosophers without, however, removing its absurdities. It is useless to revert to all the absurd theories which have from time to time distracted the metaphysical world, and which have been originated for no other purpose than to uphold the still greater absurdity of immaterialism. Philosophers of ancient times imagined the existence of an immaterial substance, unextended in its nature, like nothing. To support this wild and vague imagination, learned metaphysicians have given birth to innumerable conjectures, in order to connect this imaginary substance with the material world.

Dr. Brown, however, being a little more wise than the immaterialists who preceded him, does not attempt to connect the mutual affections, existing between matter and mind, by substituting some conjectural intervening causes. Instead of this, he advocates the direct affection of the mind by the presence of material objects—that the change of state in the one is produced by the change of state in the other, independently of intervening causes. Now this, in our view, is really what happens.

We believe that matter can only act upon mind because mind is an extended material substance. But Dr. Brown supposes there is no absurdity in matter acting upon that which is unextended. He endeavours to substantiate the possibility of the direct mutual affections of mind and matter, by referring to some examples of matter acting upon matter as in gravitation. (Brown's Philosophy of the Human Mind. Lecture XXX.) But we do not conceive these cases to be in the least analogous; for there is no absurdity in supposing one extended substance to act upon another which is also extended. But for extended substances with parts to act upon unextended substances is without a parallel, and inconceivably absurd. Indeed there could be no action at all; an immaterial mind could not act upon an immaterial mind any more than nothing could act upon nothing. To talk about matter affecting that which is inextended and without parts, is to talk about matter affecting nothing.

The very fact of the external organs affecting the mind without any intervening cause, the same as other matter affects other matter, is an argument of the strongest kind in favour of the materiality of mind. A piece of iron is affected in a certain manner by introducing into its presence a loadstone, so the mind is affected in a certain manner by the presence of light upon the retina, or by the presence or odour upon the olfactory nerve. If, then, mind can be directly affected by other substances, the same as matter directly affects matter, why should it be called an immaterial substance?

If resistance to our muscular efforts, as Dr. Brown supposes, be our only test of solidity and extension, and consequently of matter, then mind itself has the greatest claims to materiality. A muscular effort is nothing more than an effort of the mind. Without the mind the muscles are incapable of any effort whatsoever. Two men stretch out their arms, press their hands together, and resist each other with great force. In this example as it is commonly said, the muscular efforts of the one are resisted by the muscular efforts of the other; but as the muscles have no power of themselves, the facts of the case are, that the mind of the one truly resists the mind of the other through the medium of their respective muscles. If that which causes resistance then be material, mind must be material.

If two bodies of iron of equal size were moving with equal velocities towards each other, upon meeting they would destroy each others motion, and the next moment, though in contact, there would be no signs of resistance; not so with the resistance which mind offers to mind through the medium of the muscular organs; the resistance can be continued at the option of the two resisting minds; hence mind exhibits resistance in a greater degree than other substances, and should, therefore, according to Dr. Brown's test, be considered material in preference to all other substances.

No two atoms of spirit or any other matter can occupy two or more places at the same time. We have never known of a circumstance of the spirit of man residing in the body and out of it at the same time. No particles of light, odour, heat, electricity, can occupy two places at once. These substances can only be extensively diffused by being extensive in quantity. The particles of light which enter the right eye are not the same which enter the left eye. Though their qualities may be exactly alike, yet they are separate individual substance, as much so as if they were millions of miles asunder. The same is true of the atoms of spirit and all other substances.