6. Further proof of the beginnings of knowledge from external causes. In the third place, the history of language is a strong proof of the correctness of the position, that the mind is first brought into action by means of the senses, and acquires its earliest knowledge from that source. At first words are few in number, corresponding to the limited extent of ideas. The vocabulary of savage tribes (those, for example, which inhabit the American continent) is in general exceedingly limited. The growth of a language corresponds to the growth of mind; it extends itself by the increased number and power of its words, nearly in exact correspondence with the multiplication and the increased complexity of thought. Now the history of all languages teaches us, that words, which were invented and brought into use one after another in the gradual way just mentioned, were first employed to express external objects, and afterward were used to express thoughts of internal origin.

Almost all the words in every language, expressive of the susceptibilities and operations of the mind, may be clearly shown to have had an external origin and application before they were applied to the mind. To IMAGINE, in its literal signification, implies the forming of a picture; to IMPRESS Conveys the idea of leaving a stamp or mark, as the seal leaves its exact likeness or stamp on wax ; to REFLECT literally means to turn back, to go over the ground again, &c. These words cannot be applied to the mind in the literal sense; the nature of the mind will not admit of such an application; the inference therefore is, that they first had an external application. Now if it be an established truth, as the history of languages seems to show that it is, that all language has a primary reference to external objects, and that there is no term expressive of mental acts which was not originally expressive of something material, the conclusion would seem to be a fair one, that the part of our knowledge which has its rise by means of the senses, is, as a general statement, first in origin. And the more so, when we combine with these views the considerations which have been previously advanced.

7. The same subject further illustrated.

And, in the fourth place, it is not too much to say, that all the observations which have been made on persons who, from their birth or at any subsequent period, have been deprived of any of the senses, and all the extraordinary facts which have come to knowledge, having a bearing on this inquiry, go strongly in favour of the views which have been given.-It appears, for instance, from the observations which have been made in regard to persons who have been deaf until a particular period, and then have been restored to the power of hearing, that they have never previously had those ideas which naturally come in by that sense. If a person has been born blind, the result is the same; or if, having the sense of sight, it has so happened that he has never seen any colours of a particular description. In the one case, he has no ideas of colours at all; and in the other, only of those colours which he has seen. It may be said, perhaps, that this is what might be expected, and merely proves the senses to be a source of knowledge, without necessarily involving the priority of that knowledge to what has an internal origin. But then observe the persons referred to a little further, and it will be found, as a general statement, that the internal powers of their minds have not been unfolded; they lay wrapped up in a great measure in their original darkness; no inward light springs up to compensate for the absence of that which, in other cases, bursts in from the outward world. This circumstance evidently tends to confirm the principles which we are endeavouring to illustrate.

Of those extraordinary instances to which we alluded, as having thrown some light on the history of our intellectual acquisitions, is the account which is given in the Memoirs of the French Academy of Sciences for the year 1703, of a deaf and dumb young man in the city of Chartres. At the age of three-and-twenty, it so happened, to the great surprise of the whole town, that he was suddenly restored to the sense of hearing, and in a short time he acquired the use of language. Deprived for so long a period of a sense which, in importance, ranks with the sight and the touch, unable to hold communion with his

fellow-beings by means of oral or written language, and not particularly compelled, as he had every care taken of him by his friends and relations, to bring his faculties into exercise, the powers of his mind remained without having opportunity to unfold themselves. Being examined by some men of discernment, it was found that he had no idea of a God, of a soul, of the moral merit or demerit of human actions, and, what might seem to be yet more remarkable, he knew not what it was to die; the agonies of dissolution, the grief of friends, and the ceremonies of interment being to him inexplicable mysteries.

Here we see how much knowledge a person was deprived of, merely by his wanting the single sense of hearing; a proof that the senses were designed by our Creator to be the first source of knowledge, and that without them the faculties of the soul would never become operative.

§ 8. Illustration from the case of James Mitchell.

But this is not the only instance of this sort which ingenious men have noticed and recorded. In the Transactions of the Royal Society at Edinburgh, (vol. vii., part i.,) is a Memoir communicated by Dugald Stewart, which gives an account of James Mitchell, a boy born deaf and blind. The history of this lad, who laboured under the uncommon affliction of this double deprivation, illustrates and confirms all that has been above stated. He made what use he could of the only senses which he possessed, those of touch, taste, and smell, and gained from them a number of ideas. It was a proof of the diligence with which he employed the limited means which were given him, that he had by the sense of touch thoroughly explored the ground in the neighbourhood of the house where he lived for hundreds of yards. But deprived of sight, of hearing, and of intercourse by speech, it was very evident to those who observed him, as might be expected, that his knowledge was in amount exceedingly small. He was destitute of those perceptions which are appropriate to the particular senses of which he was deprived; and also of many other notions of an internal origin, which would undoubtedly have arisen, if the

powers of the mind had previously been rendered fully operative by means of those assistances which it usually receives from the bodily organs.-Such instances as these, however they may at first appear, are extremely important. They furnish us with an appeal, not to mere speculations, but to fact. And it is only by checking undue speculation, and by continually recurring to facts, that our progress in this science will become sure, rapid, and delightful.

CHAPTER II.

SENSATION AND PERCEPTION.

9. Sensation a simple mental state originating in the senses.

In tracing the history of that portion of human thought which is of external origin, we have frequent occasion to make use of the words Sensation and Perception. The term SENSATION is not of so general a nature as to include every variety of mental state, but is limited to such as answer to a particular description. It does not appear that the usage of language would forbid our speaking of the feelings of warmth, and coldness, and hardness, as well as of the feelings of love, and benevolence, and anger, but it would clearly forbid our using the term SENSATION with an application equally extensive. Its application is not only limited, but is fixed with a considerable degree of precision.

Sensation, being a simple act or state of the mind, is unsusceptible of definition; and this is one of its characteristics. As this alone, however, would not separate it from many other mental states, it has this peculiarity to distinguish it, that it is immediately successive to a change in some organ of sense, or, at least, to a bodily change of some kind. But it is evident, that, in respect to numerous other feelings, this statement does not hold good. They are immediately subsequent, not to bodily impressions, but to other states of the soul itself. Hence it is, that

while we speak of the sensations of heat and cold, of hardness, of smoothness, roughness, and the like, we do not commonly apply this term to joy and sorrow, hatred and love, and other emotions and passions.

§ 10. All sensation is properly and truly in the mind.

Sensation is often regarded as something having a position, and as taking place in the body, and particularly in the organ of sense. The sensation of touch, as we seem to imagine, is in the hand, which is the organ of touch, and is not truly internal; the hearing is in the ear, and the vision in the eye, and not in the soul. But all we can say with truth and on good grounds is, that the organs of sense are accessory to sensation and necessary to it; but the sensation or feeling itself is wholly in the mind. How often it is said the eye sees; but the proper language, if we look at the subject philosophically, is, that the soul sees; for the eye is only the organ, instrument, or minister of the soul in visual perceptions.

"A man," says Dr Reid, "cannot see the satellites of Jupiter but by a telescope. Does he conclude from this that it is the telescope that sees those stars? By no means; such a conclusion would be absurd. It is no less absurd to conclude that it is the eye that sees, or the ear that hears. The telescope is an artificial organ of sight, but it sees not. The eye is a natural organ of sight, by which we see; but the natural organ sees as little as the artificial."

11. Sensations are not images or resemblances of objects. But while we are careful to assign sensations their true place in the mind, and to look upon what is outward in the body as merely the antecedents or cause of them, it is a matter of some consequence to guard against a danger directly the reverse of that which has been remarked on. We are apt to transfer to the sensation, considered as existing in the mind, some of those qualities which belong to the external object. But in point of fact, our sensations are by no means copies, pictures, or images of outward objects; nor are they representations of them in any material sense whatever ; nor do they possess any of their qualities. C