However, if any case should happen, in which sounds produced by different causes are not distinguishable by the ear, this may prove that our senses are imperfect, but not that they are fallacious. The ear may not be able to draw the just conclusion, but it is only our ignorance of the laws of sound that leads us to a wrong conclusion.

Deceptions of sight, arising from ignorance of the laws of nature, are more numerous, and more remarkable than those of hearing.

The rays of light, which are the means of seeing, pass in right lines from the object to the eye, when they meet with no obstruction; and we are-by nature led to conceive the visible object to be in the direction of the rays that come to the eye. But the rays may be reflected, refracted, or inflected in their passage from the object to the eye, according to certain fixed laws of nature, by which means their direction may be changed, and consequently the apparent place, figure, or magnitude of the object.

Thus a child seeing himself in a mirror, thinks he sees another child behind the mirror, that imitates all his motions. But even a child soon gets the better of this deception, and knows that he sees himself only.

All the deceptions made by telescopes, microscopes, camera obscuras, magic lanthorns, are of the same kind, though not so familiar to the vulgar. The ignorant may be deceived by them; but to those who are acquainted with the principles of optics, they give just and true information, and the laws of nature by which they are produced are of infinite benefit to mankind.

There remains another class of errors, commonly called deceptions of sense, and the only one, as I apprehend, to which that name can be given with propriety: I mean such as proceed from some disorder or preternatural state, either of the external organ, or of the nerves and brain, which are internal organs of perception.

In a delirium, or in madness, perception, memory, imagination, and our reasoning powers, are strangely disordered and confounded. There are likewise disorders which affect some of our senses, while others are sound. Thus, a man may feel pain in his toes after the leg is cut off. He may feel a little ball double, by crossing his fingers. He may see an object double, by not directing both eyes properly to it. By pressing the ball of his eye, he may see colours that are not real. By the jaundice in his eyes, he may mistake colours. These are more properly deceptions of sense than any of the classes before mentioned.

We must acknowledge it to be the lot of human nature, that all the human faculties are liable, by accidental causes, to be hurt and unfitted for their natural functions, either wholly or in part: but as this imperfection is common to them all, it gives no just ground for accounting any of them fallacious more than another.

Upon the whole, it seems to have been a common error of philosophers to account the senses fallacious. And to this error they have added another, that one use of reason is to detect the fallacies of sense.

It appears, I think, from what has been said, that there is no more reason to account our senses fallacious, than our reason, our memory, or any other faculty of judging which nature hath given us. They are all limited and imperfect; but wisely suited to the present condition of man. We are liable to error and wrong judgment in the use of them all; but as little in the informations of sense as in the deductions of reasoning. And the errors we fall into with regard to objects of sense are not corrected by reason, but by more accurate attention to the informations we may receive by our senses themselves.

Perhaps the pride of philosophers may have given occasion to this error. Reason is the faculty wherein they assume a superiority to the unlearned. The informations of sense are common to the philosopher and to the most illiterate they put all men upon a level; and therefore are apt to be undervalued. We must, however, be beholden to the informations of sense for the greatest and most interesting part of our knowledge. The wisdom of nature has made the most useful things most common, and they ought not to be despised on that account. Nature likewise forces our belief in those informations, and all the attempts of philosophy to weaken it are fruitless and vain.

I add only one observation to what has been said upon this subject. It is, that there seems to be a contradiction between what philosophers teach concerning ideas, and their doctrine of the fallaciousness of the senses. We are taught, that the office of the senses is only to give us the ideas of external objects. If this be so, there can be no fallacy in the senses. Ideas can neither be true nor false. If the senses testify nothing, they cannot give false testimony. If they are not judging faculties, no judgment can be imputed to them, whether false or true. There is, therefore, a contradiction between the common doctrine concerning ideas and that of the fallaciousness of the senses. Both may be false, as I believe they are, but both cannot be true.

ESSAY III.

OF MEMORY.

CHAPTER I.

THINGS OBVIOUS AND CERTAIN WITH REGARD TO MEMORY.

IN the gradual progress of man, from infancy to maturity, there is a certain order in which his faculties are unfolded, and this seems to be the best order we can follow in treating of them.

The external senses appear first; memory soon follows, which we are now to consider.

It is by memory that we have an immediate knowledge of things past : the senses give us information of things only as they exist in the present moment; and this information, if it were not preserved by memory, would vanish instantly, and leave us as ignorant as if it had never been.

Memory must have an object. Every man who remembers must remember something, and that which he remembers is called the object of his remembrance. In this memory agrees with perception, but differs from sensation, which has no object but the feeling itself.

Every man can distinguish the thing remembered from the remembrance of it. We may remember any thing which we have seen, or heard, or known, or done, or suffered; but the remembrance of it is a particular act of the mind which now exists, and of which we are conscious. To confound these two is an absurdity, which a thinking man could not be led into, but by some false hypothesis which hinders him from reflecting upon the thing which he would explain by it.

In memory we do not find such a train of operations connected by our constitution as in perception. When we perceive an object by our senses, there is, first, some impression made by the object upon the organ of sense, either immediately or by means of some medium. By this an impression is made upon the nerves and brain, in consequence of which we feel some sensation; and that sensation is attended by that conception and belief of the external object which we call perception. These operations are so connected in our constitution, that it is difficult to disjoin them in our conceptions, and to attend to each without confounding it with the others. But in the operations of memory we are free from this embarrassment; they are easily distinguished from all other acts of the mind, and the names which denote them are free from all ambiguity.

The object of memory, or thing remembered, must be something that is past; as the object of perception and of consciousness must be something which is present: what now is, cannot be an object of memory; neither can that which is past and gone be an object of perception or of conscious

ness.

Memory is always accompanied with the belief of that which we remember, as perception is accompanied with the belief of that which we

perceive, and consciousness with the belief of that whereof we are conscious. Perhaps in infancy, or in a disorder of mind, things remembered may be confounded with those which are merely imagined; but in mature years, and in a sound state of mind, every man feels that he must believe what he distinctly remembers, though he can give no other reason of his belief, but that he remembers the thing distinctly; whereas, when he merely imagines a thing ever so distinctly, he has no belief of it upon that account.

This belief, which we have from distinct memory, we account real knowledge, no less certain than if it was grounded on demonstration; no man in his wits calls it in question, or will hear any argument against it. The testimony of witnesses in causes of life and death depends upon it, and all the knowledge of mankind of past events is built on this foundation.

There are cases in which a man's memory is less distinct and determinate, and where he is ready to allow that it may have failed him; but this does not in the least weaken its credit, when it is perfectly distinct.

Memory implies a conception and belief of past duration; for it is impossible that a man should remember a thing distinctly, without believing some interval of duration, more or less, to have passed between the time it happened, and the present moment; and I think it is impossible to show how we could acquire a notion of duration if we had no memory.

Things remembered must be things formerly perceived or known. I remember the transit of Venus over the sun in the year 1769. I must therefore have perceived it at the time it happened, otherwise I could not now remember it. Our first acquaintance with any object of thought cannot be by remembrance. Memory can only produce a continuance or renewal of a former acquaintance with the thing remembered.

The remembrance of a past event is necessarily accompanied with the conviction of our own existence at the time the event happened. I cannot remember a thing that happened a year ago, without a conviction, as strong as memory can give, that I, the same identical person who now remember that event, did then exist.

What I have hitherto said concerning memory, I consider as principles which appear obvious and certain to every man who will take the pains to reflect upon the operations of his own mind. They are facts of which every man must judge by what he feels; and they admit of no other proof but an appeal to every man's own reflection. I shall therefore take them for granted in what follows, and shall first draw some conclusions from them, and then examine the theories of philosophers concerning memory, and concerning duration, and our personal identity, of which we acquire the knowledge by memory.

CHAPTER II.

MEMORY AN ORIGINAL FACULTY.

FIRST, I think it appears that memory is an original faculty given us by the Author of our being, of which we can give no account, but that we are so made.

The knowledge which I have of things past, by my memory, seems to me as unaccountable as an immediate knowledge would be of things to come; and I can give no reason why I should have the one and not the other, but that such is the will of my Maker. I find in my mind a

It is the

distinct conception and a firm belief of a series of past events; but how this is produced I know not. I call it memory, but this is only giving a name to it; it is not an account of its cause. I believe most firmly what I distinctly remember; but I can give no reason of this belief. inspiration of the Almighty that gives me this understanding. When I believe the truth of a mathematical axiom, or of a mathematical proposition, I see that it must be so every man who has the same conception of it sees the same. There is a necessary and an evident connexion between the subject and the predicate of the proposition; and I have all the evidence to support my belief which I can possibly conceive. When I believe that I washed my hands and face this morning, there appears no necessity in the truth of this proposition. It might be, or it might not be. A man may distinctly conceive it without believing it at all. How then do I come to believe it? I remember it distinctly. This is all I can say. This remembrance is an act of my mind. It is impossible that this act should be, if the event had not happened. I confess I do not see any necessary connexion between the one and the other. If any man can show such a necessary connexion, then I think that belief which we have of what we remember will be fairly accounted for; but if this cannot be done, that belief is unaccountable, and we can say no more but that it is the result of our constitution.

Perhaps it may be said, that the experience we have had of the fidelity of memory is a good reason for relying upon its testimony. I deny not that this may be a reason to those who have had this experience, and who reflect upon it. But I believe there are few who ever thought of this reason, or who found any need of it. It must be some very rare occasion that leads a man to have recourse to it; and in those who have done so, the testimony of memory was believed before the experience of its fidelity, and that belief could not be caused by the experience which came after it.

We know some abstract truths, by comparing the terms of the proposition which expresses them, and perceiving some necessary relation or agreement between them. It is thus know that two and three make five that the diameters of a circle are all equal. Mr. Locke having discovered this source of knowledge, too rashly concluded that all human knowledge might be derived from it; and in this he has been followed very generally; by Mr. Hume in particular.

But I apprehend, that our knowledge of the existence of things contingent can never be traced to this source. I know that such a thing exists, or did exist. This knowledge cannot be derived from the perception of a necessary agreement between existence and the thing that exists, because there is no such necessary agreement; and therefore no such agreement can be perceived either immediately, or by a chain of reasoning. The thing does not exist necessarily, but by the will and power of him that made it and there is no contradiction follows from supposing it not to exist.

:

Whence I think it follows, that our knowledge of the existence of our own thoughts, of the existence of all the material objects about us, and of all past contingencies, must be derived, not from a perception of necessary relations or agreements, but from some other source.

Our Maker has provided other means for giving us the knowledge of these things; means which perfectly answer their end, and produce the effect intended by them. But in what manner they do this, is, I fear, beyond our skill to explain. We know our own thoughts, and the operations of our minds, by a power which we call consciousness: but this is