The Mode of Operation.—The process through which the mind passes in such a case, is, to dwell upon some circumstances not forgotten, that are intimately connected with the missing idea, and through these, as so many connecting links, to pass over, if possible, to the thing sought. I cannot, for example, recall the name, but I remember the names of other persons of the same family, class, or profession, or I remember that it begins with the letter B, and then think over all the names I know that begin with that letter; and, in this way, seek to recall, by association, the name that has escaped.
Memory not an immediate Knowledge.—It has been held by some that memory gives us an immediate knowledge of the past. This is the view of Dr. Reid. If, by immediate knowledge, we mean knowledge of a thing as existing, and as it is in itself—nothing intervening between it as a present reality, and our direct cognizance of it—then not in this sense is memory an immediate knowledge; for a past event is no longer existent, and cannot be known as such, or as it is in itself; it no longer is, but only was. Hence an immediate knowledge of it, is, as Sir William Hamilton affirms, a contradiction. Still, we may know the past as it was, not less really and positively than we know the present as it is. I as really know that I sat at this table yesterday as I know that I sit here now. I am conscious of being here now. I was conscious of being here then. That consciousness is not to be impeached in either case. If the senses deceived me yesterday, they may deceive me to-day. If consciousness testified falsely then, it may now. But if I was indeed here yesterday, and if I knew then that I was here, and that knowledge was certain and positive, then I know now that I was here yesterday, for memory recognizes what would otherwise be the mere conception of to-day, as identical with the positive knowledge of yesterday. Memory may possibly be mistaken as to the so-called positive knowledge of yesterday; and so sense may be mistaken as to the so-called positive knowledge of the present moment.
Belief attending Memory.—The remarks of Dr. Reid on this point are worthy of note. "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 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 for 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."
Importance of this Faculty.—The importance of memory as a power of the mind, is shown by the simple fact, that, but for it, there could be no consciousness of continued existence, none of personal identity, for memory is our only voucher for the fact that we existed at all at any previous moment. Without this faculty, each separate instant of life would be a new existence, isolated, disconnected with aught before or after; nay, there would, in that case, scarcely be any consciousness of even the present existence, for we are conscious only as we are cognizant of change, says Hamilton, and there is involved in it the idea of the latest past along with the present. Memory, then, is essential to all intelligent mental action, whether intellectual, sensational, or voluntary. The ancients seem to have been aware of this, when they gave it the name μνηνη (from μνηνοσ, μναομαι), appellations of the mind itself, as being, in fact, the chief characteristic faculty of the mind.
II. What is implied in an Act of Memory.
Several Conditions.—Every act of memory involves these several conditions: 1. Present existence. 2. Past existence. 3. Mental activity at some moment of that past existence. 4. The recurrence to the mind of something thus thought, perceived, or felt. 5. Its recognition as a past or former thought or impression, and that our own. These last, the recurrence and the recognition, are strictly the essential elements of memory, yet the others are implied in it. In order to my remembering, for example, an occurrence of yesterday, I must exist at the present time, else I cannot remember at the present time; I must have existed yesterday, else there can be no memory of yesterday; my mind must have been active then, else there will be nothing to remember; the thoughts, perceptions, sensations, then occupying the mind, must now recur, else it is the same as if they had never been; they must recur, not as new thoughts and impressions, but as old ones, else I no longer remember, but only conceive or perceive.
III. Qualities of Memory.
Distinctions of Stewart and Wayland.—It has been customary to designate certain qualities as essential to a good memory. Susceptibility, retentiveness, and readiness, are thus distinguished by Mr. Stewart; the first denoting the facility with which the mind acquires; the second, the permanence with which it retains; and the third, the quickness with which it recalls and applies its original acquisitions. And these qualities are rarely united, he adds, in the same person. The memory which is susceptible and ready, is not commonly very retentive. Dr. Wayland makes the same distinction. Some men, he says, retain their knowledge more perfectly than they recall it. Others have their knowledge always at command. Some men acquire with great rapidity, but soon forget what they have learned. Others acquire with difficulty, but retain tenaciously.
Objections to this View.—Although supported by such authority, it admits of question whether this distinction is strictly valid. Facility of acquisition, the readiness with which the mind perceives truth, is hardly to be reckoned as an attribute of memory. It is a quality of mind, a quality possessed in diverse degrees by different persons, doubtless, but not a quality of mind in its distinctive capacity and office of remembering. It is no part, psychologically considered, of the function of mental reproduction. It is essential, indeed, to the act of memory that there should be something to remember, but the acquisition of the thing remembered, and the remembering, are two distinct and different mental acts; nor is it of any consequence to the mind, in remembering, whether the original acquisition was made with more or less facility. Indeed, so far as that bears upon the case at all, facility of acquisition, as even these writers admit, is likely to be rather a hindrance than a help to subsequent remembrance, since what is most readily acquired is not most readily recalled.