although it be a voluntary act, it requires experience to have it always under command. In the case of objects to which we have been taught to attend at an early period of life, or which are calculated to rouse the curiosity, or to affect any of our passions, the attention fixes itself upon them, as it were spontaneously, and without any effort on our part, of which we are conscious. How perfectly do we remember, and even retain, for a long course of years, the faces and the handwritings of our acquaintances, although we never took any particular pains to fix them in the memory? On the other hand, if an object does not interest some principle of our nature, we may examine it again and again, with a wish to treasure up the knowledge of it in the mind, without our being able to command that degree of attention which may lead us to recognise it the next time we see it. A person, for example, who has not been accustomed to attend particularly to horses or to cattle, may study for a considerable time the appearance of a horse or of a bullock without being able a few days afterwards to pronounce on its identity; while a horse-dealer or a grazier recollects many hundreds of that class of animals with which he is conversant, as perfectly as he does the faces of his acquaintances. In order to account for this, I would remark, that although attention be a voluntary act, and although we are always able, when we choose, to make a momentary exertion of it; yet, unless the object to which it is directed be really interesting, in some degree, to the curiosity, the train of our ideas goes on, and we immediately forget our purpose. When we are employed, therefore, in studying such an object, it is not an exclusive and steady attention that we give to it, but we are losing sight of it, and recurring to it every instant; and the painful efforts of which we are conscious, are not (as we are apt to suppose them to be) efforts of uncommon attention, but unsuccessful attempts to keep the mind steady to its object, and to exclude the extraneous ideas, which are from time to time soliciting its notice.

If these observations be well founded, they afford an explanation of a fact which has been often remarked, that objects are

easily remembered which affect any of the passions.1 The passion assists the memory, not in consequence of any immediate connexion between them, but as it presents, during the time it continues, a steady and exclusive object to the attention.

The connexion between memory and the association of ideas is so striking, that it has been supposed by some that the whole of its phenomena might be resolved into this principle. But this is evidently not the case.-The association of ideas connects our various thoughts with each other, so as to present them to the mind in a certain order; but it presupposes the existence of these thoughts in the mind; or, in other words, it presupposes a faculty of retaining the knowledge which we acquire. It involves also a power of recognising, as former objects of attention, the thoughts that from time to time occur to us; a power which is not implied in that law of our nature which is called the association of ideas. It is possible, surely, that our thoughts might have succeeded each other, according to the same laws as at present, without suggesting to us at all the idea of the past; and, in fact, this supposition is realized to a certain degree in the case of some old men, who retain pretty exactly the information which they receive, but are sometimes unable to recollect in what manner the particulars which they find connected together in their thoughts at first came into the mind; whether they occurred to them in a dream, or were communicated to them in conversation.

On the other hand, it is evident that, without the associating principle, the powers of retaining our thoughts, and of recognising them when they occur to us, would have been of little use; for the most important articles of our knowledge might have remained latent in the mind, even when those occasions presented themselves to which they are immediately applicable. In consequence of this law of our nature, not only are all our

1 "Si quas res in vita videmus parvas, usitatas, quotidianas, eas meminisse non solemus; propterea quod nulla nisi nova aut admirabili re commovetur animus. At si quid videmus aut audimus egregie

turpe, aut honestum, inusitatum, magnum, incredibile, ridiculum, id diu meminisse consuevimus."—[Cicero ?] Ad Herenn, lib. 3.

various ideas made to pass, from time to time, in review before us, and to offer themselves to our choice as subjects of meditation, but when an occasion occurs which calls for the aid of our past experience, the occasion itself recalls to us all the information upon the subject which that experience has accumulated.

The foregoing observations comprehend an analysis of memory sufficiently accurate for my present purpose: some other remarks, tending to illustrate the same subject more completely, will occur in the remaining sections of this chapter.

It is hardly necessary for me to add, that when we have proceeded so far in our inquiries concerning memory, as to obtain an analysis of that power, and to ascertain the relation in which it stands to the other principles of our constitution, we have advanced as far towards an explanation of it as the nature of the subject permits. The various theories which have attempted to account for it by traces or impressions in the sensorium, are obviously too unphilosophical to deserve a particular refutation.1 Such, indeed, is the poverty of language, that we cannot speak on the subject without employing expressions which suggest one theory or another; but it is of importance for us always to recollect, that these expressions are entirely figurative, and afford no explanation of the phenomena to which they refer. It is partly with a view to remind my readers of this consideration, that, finding it impossible to lay aside completely metaphorical or analogical words, I have studied to avoid such a uniformity in the employment of them, as might indicate a preference to one theory rather than another; and, by doing so, have perhaps sometimes been led to vary the metaphor oftener and more suddenly than would be proper in a composition which aimed at any degree of elegance. This caution in the use of the common language concerning memory it seemed to me the more necessary to attend to, that the general disposition which every person feels, at the commencement of his philosophical pursuits, to explain the phenomena of thought by the laws of matter, is, in the case of this particular faculty, encouraged by

1 See Note S.

a variety of peculiar circumstances. The analogy between committing a thing to memory that we wish to remember, and engraving on a tablet a fact that we wish to record, is so striking as to present itself even to the vulgar; nor is it perhaps less natural to indulge the fancy in considering memory as a sort of repository, in which we arrange and preserve for future use the materials of our information. The immediate dependence, too, of this faculty on the state of the body, which is more remarkable than that of any other faculty whatever, (as appears from the effects produced on it by old age, disease, and intoxication,) is apt to strike those who have not been much conversant with these inquiries, as bestowing some plausibility on the theory which attempts to explain its phenomena on mechanical principles.

I cannot help taking this opportunity of expressing a wish that medical writers would be at more pains than they have been at hitherto, to ascertain the various effects which are produced on the memory by disease and old age. These effects are widely diversified in different cases. In some it would seem that the memory is impaired, in consequence of a diminution of the power of attention; in others, that the power of recollection is disturbed, in consequence of a derangement of that part of the constitution on which the association of ideas depends. The decay of memory, which is the common effect of age, seems to arise from the former of these causes. It is probable that, as we advance in years, the capacity of attention is weakened by some physical change in the constitution; but it is also reasonable to think, that it loses its vigour partly from the effect which the decay of our sensibility and the extinction of our passions have in diminishing the interest which we feel in the common occurrences of life. That no derangement takes place, in ordinary cases, in that part of the constitution on which the association of ideas depends, appears from the distinct and circumstantial recollection which old men retain of the transactions of their youth. In some diseases, this part of the con

1

[Instances of this are so common,

that there can be no dispute about the

fact. At the same time, I agree with Dr. Hartley in thinking. (Observations

stitution is evidently affected. A stroke of the palsy has been known (while it did not destroy the power of speech) to render the patient incapable of recollecting the names of the most familiar objects. What is still more remarkable, the name of