strictly speaking, it has no unity except in our thought.

There is nothing in a mass of matter which is not in all its particles, nor is there any power in the mass except the united powers of the particles. The attractive power of the sun, or of a planet, is only the sum of the attractive powers of all its particles. Thought, therefore, can never result from the mere combined powers of an organised body, for the powers of such a body can only be the aggregate powers of its particles; but thought is not an aggregation of powers, but one, simple, and indivisible: and the being which thinks is not an assemblage of beings, but one, simple, and indivisible.

We must, therefore, conclude that there is something in man besides his organised body, something which thinks and wills, which is one and indivisible, and which is totally different, in nature, from any thing that we conceive of matter. To this we give the name of Mind or Spirit.

We know nothing at all of the substance or essence either of matter or of spirit. But from the great apparent difference of their qualities and powers we have reason to think them essentially different. Nor have we, indeed, any knowledge that matter itself is one uniform substance: it may, perhaps, be rather a class of substances, all different from one another, though agreeing in some particulars. But, be this as it may, there is a marked difference between this class of substances

and spirit. Matter is extended and solid, resisting our efforts to compress it. To spirit, by reason of its indivisibility, neither extension nor solidity can be ascribed with propriety, though we do not deny it the necessary attribute of space, any more than duration; but it is that which thinks, and desires, and wills. We know matter only in masses which are divisible; spirit only in individuals which are indivisible. I forbear to ascribe

infinite divisibility to matter. We know nothing

of this. It is true that we cannot reach its smallest particles by any division: divide it as we may, it still is capable of farther division; and it is true that mathematicians have demonstrated, that in thought, we can go on dividing it ad infinitum. But still it may have ultimate and indivisible particles, -indivisible in reality, although they may be divided in thought.

It is his mind, therefore, which gives unity to a man,-which constitutes him what he is, ONE CONSCIOUS THINKING AND ACTIVE BEING. It is his thought, and that alone, which confers a seeming unity on the material objects which he sees around him. Even his own body, though organised, derives all its unity from the soul which animates it.

Extension, solidity, and form are not predicable of thought. We do not speak of a thought as a yard or an inch long or broad, nor do we speak of it as square or cubical. Nevertheless we do speak

of sensations as extended in length and breadth, and sometimes also in depth. Thus a man will say that a pain extends all along and across his breast, and through to his back. This is a remarkable circumstance, and somewhat difficult to explain. Men of little education account for it by supposing that the mind is the seat of thought, but the body the seat of sensation. On thinking a little more deeply on the subject they discern difficulties attending that view, and are ready to fall in with the prevailing opinion of philosophers, that both sensation and thought belong solely to the mind. On which of these suppositions the greatest difficulties attend, may still, however, be regarded as problematical.

CHAPTER V.

ORIGIN OF OUR IDEAS OF THE MATERIAL WORLD NOT SATIS

FACTORILY

EXPLAINED BY PHILOSOPHERS CANNOT BE

ACCOUNTED FOR ON THE COMMON THEORY OF SENSATION.

SECTION I.

IN entering on the consideration of the varied phenomena of the Intellectual and Moral World, the first which claim our attention are our ideas of the Material World. These are naturally the first of which the child is sensible, and on them all the ideas which he subsequently forms are obviously engrafted they have, at the same time, superior force and clearness; and therefore it is both interesting in its own nature, and necessary for the security of our subsequent progress, to enquire into their origin. The name of Perception has been given to that operation of the mind by which it becomes acquainted with external objects. Much has been written on the subject, and had

all the reasonings by which the ingenious have endeavoured to illustrate it been properly directed, our knowledge, with regard to it, might now have been at a much higher stage of advancement.

There is an extreme difficulty in conceiving how matter can act on mind, and it is this which has led to most of the theories which have been advanced. These are in general founded on mere unsatisfactory conjectures.

Aristotle conceived that there are sensible species or images of external things, constantly proceeding from objects in every direction; that these are admitted to the mind by the senses, and thus constitute our only objects of perception. This notion has some slight appearance of foundation, in the phenomena belonging to the sense of sight, but is quite unintelligible when extended to the other senses. Some indulgence, however, is due to the first dawning of enquiry upon the abstruse and difficult subject of perception. Truth is frequently discovered only by the correction of errors. And, instead of treating with contempt and arrogance the opinions of those, who, at an early period, turned their thoughts to the subject, we should regard with some degree of gratitude those ingenious men who have directed the attention of philosophers to any new subject worthy of enquiry.

Des Cartes rejected the hypothesis of Aristotle, and substituted in its place the doctrine of animal