394. All limited Duration is comprehended in Time, and all limited Extension, in Space. These, in their capacious womb, contain all finite existences, but are contained by

none.

Illus. Created things have their particular places in space, and their particular places in time; but time is every where, and space at all times; therefore you, and I, and all of us, who, in the language of Trim, "are here to-day and gone to-morrow," have our particular places in space, and our particular places in time. Time and space embrace each the other, and have that mysterious union which the schoolmen conceived between soul and body-the whole of each is in every part of the other.

CHAPTER V.

OF IDENTITY.

395. IN treating of Memory, one of our positions runs thus: "The remembrance of a past event is necessarily accompanied with the conception of our own EXISTENCE at the time the event happened.' (Art. 245.)

Obs. The conviction which each of us has of his own Identity, as far back as his memory reaches, needs no aid of philosophy to give it strength; nor can it be weakened by any philosophy, without first producing some degree of insanity.

396. This conviction is indispensably necessary to all exercise of reason. The operations of reason, whether in action or in speculation, are made up of successive parts. The antecedent operations are the foundation of the consequent (Art. 132. Illus. and Art. 133.); and without the conviction that the antecedent have been seen or done by me, I could have no reason to proceed to the consequent, in any speculation, or in any active project whatever.

Obs. That we may form as distinct a notion as we are able of this phenomenon of the human mind, it is proper to consider, first, What is meant by Identity in general; Secondly, What by our own personal Identity; and how we are led to that invincible belief and conviction, which every man has of his own personal Identity, to any period in which his memory is present.

I. What is meant by Identity in General.

397. Dr. Reid takes Identity in general to be a relation between a thing which is known to exist at one time, and a thing which is known to have existed at another. If you ask,

"Whether they are one and the same, or two different things," every man of common sense understands perfectly the meaning of your question.

Corol. Whence we may infer with certainty, that every man of common sense has a clear and distinct notion of Identity. (See Art. 5.)

Obs. The term Identity conveys a notion too simple for a logical definition. It conveys an idea of relation, which none confound with other relations.

398. Identity supposes an uninterrupted continuance of existence. (See Art. 52. Illus. 1 and 2.)

Illus. That which hath ceased to exist, cannot be the same with that which afterwards begins to exist; for this would be to suppose a being to exist after it had ceased to exist, and to have had existence before it was produced, which are manifest contradictions. Continued and uninterrupted existence is, therefore, necessarily implied in Identity.

Corol. Hence we may infer, that Identity cannot, in its proper sense, be applied to our pains, our pleasures, our thoughts, or any operations of our minds. The headache I feel this day is not the same individual headache which I felt yesterday; though, as far as I can judge, they are similar in kind and intensity of pain, and probably have the same cause. The same may be said of every feeling, and of every operation of mind; they are all successive in their nature, like time itself, no two moments of which can be the same moment. It is otherwise with the parts of space: they always are, they always were, and they always will be the same.

Note. The ground does not appear any further clear, in fixing the notion of Identity in general.

II. Of Personal Identity.

399. It is, perhaps, more difficult to fix with precision the meaning of personality; but it is not necessary in the present subject. It is sufficient for our purpose to observe, that all mankind place their personality in something that cannot be divided, or that cannot consist of parts. A part of you or of me, is a manifest absurdity.

Illus. When a man loses his estate, his health, his strength, he is still the same person, and has lost nothing of his personality. The Marquis of Anglesea lost a leg at the battle of Waterloo, but he is the same person he was before. A person is something indivisible, and is

what LEIBNITZ calls a monad.

400. Any personal identity, therefore, implies the continued existence of that indivisible thing, which I call myself. (Art. 52.)

Illus. Whatever this self may be, it is something which thinks, and deliberates, and resolves, and acts, and suffers. I am not

thought, nor action, nor feeling; yet am I something that thinks, and acts, and suffers. My thoughts, and actions, and feelings, change every moment; they have no continued, but a successive existence; but that self, or I, to which they belong, am permanent, and have the same relation to all the succeeding thoughts, actions, and feelings, which 1 call mine.

401. Such are the notions that I have of my personal Identity. But perhaps it may be said, this is all fancy, without reality; and the skeptic may demand, How do you know, what evidence have you, that there is such a permanent self, which has a claim to all the thoughts, actions, and feelings, which you call yours?

Illus. To this I answer, that the proper evidence which I have of all this, is remembrance. (See Art. 246. and its Illustrations.) I remember, that, in the year 1814, I published "A Treatise on the Construction of Maps." I remember several things that happened while that work was printing; and among these, that my friend, Peter Nicholson, very obligingly read over the proof sheets of that work for me. My memory testifies, not only that the book in question was printed, but that it was printed from a manuscript, which 1, who now remember, wrote or compiled. Supposing that no copy of this work were now extant; still, if it was done by me, I must have existed at that time, and continued to exist, in one place or another, from that time to the present. If the identical person, whom I call myself, did not write that book, my memory is fallacious; it gives a distinct and positive testimony of what is not true. But every man in his senses believes what he distinctly remembers; and every thing he remembers, convinces him, that he existed at the time remembered.

402 When we pass judgment on the Identity of other persons besides ourselves, we proceed upon other grounds, and determine from a variety of circumstances, which sometimes produce the firmest assurance, and sometimes leave room for doubt.

Obs. The Identity of persons has often furnished matter of serious litigation, before tribunals of justice.

Ilus. The Identity of a person is a perfect identity; wherever it is real, it admits of no degrees; and it is impossible that a person should be in part the same, and in part different; because a person is a monad, and is not divisible into parts. The evidence of Identity in other persons besides ourselves, does indeed admit of all degrees, from what we account certainty, to the least degree of probability. But still it is true, that the same person is perfectly the same, and cannot be so in part, or in some degree only. The honest Hibernian who accosted a stranger in London, saying, "I thought it was you, but I see now it is your brother;" though the author of a sad bull, affords a happy illustration of the judgment we pass on other persons besides ourselves.

403. Our judgments of the Identity of objects of sense seem to be formed much upon the same grounds as our judgments of the Identity of other persons besides the selfidentity which we have of ourselves.

Illus. 1. Wherever there is great similarity, we are apt to presume Identity, if no reason appears to the contrary: when two objects, ever so like, are perceived at the same time, they cannot be the same. But if they are presented to our senses at different times, we are apt to think them the same, merely from their similarity.

2. Whether this is a natural prejudice, or from what cause soever it proceeds, it certainly appears in children from infancy; and when they grow up, it is confirmed, in most instances, by experience; for, of the same species, men rarely find two individuals that are not distinguishable by obvious differences.

Example. A man challenges a thief whom he finds in possession of his horse or his watch, only on similarity. When the watchmaker swears, that he sold this watch to such a person, his testimony is grounded on similarity. The testimony of witnesses to the identity of a person, is commonly grounded on no better evidence.

Corol. Thus it appears, that the evidence we have of our own Identity, as far back as we remember, is totally of a different kind from the evidence we have of the Identity of other persons, or of objects of sense. The first is grounded on memory, and gives undoubted certainty the last is grounded on similarity, and on other circumstances, which, in many cases, are not so decisive as to leave no room for doubt.

404. The Identity of objects of sense is never perfect, because, as they consist of parts, which, from a variety of causes, are subject to continual changes, the substances of which they are made up, are insensibly changing, increasing, or diminishing.

Illus. Thus we say of an old regiment, the 42d, for example, that it scaled the heights of Abraham at Quebec, though there now is not a man alive that belonged to it then. Also a ship of war, which has successively changed her anchors, her tackle, her sails, her masts, her planks, and her timbers, while she keeps the same name, is still the

same.

Corol. 1. The Identity, therefore, which we ascribe to bodies, whether natural or artificial, is not perfect Identity; it is rather something, which, for the conveniency of speech, we call Identity. It admits of great change of the subject, providing the change be gradual, sometimes even of a total change; as that of my countryman's pistol, which, with a new stock, a new lock, and a new barrel, was still his old pistol.

2. And the changes, which, in common language, are made consistently with Identity, differ from those that are thought to destroy it, not in kind, but in number and degree. It has no fixed nature when applied to bodies; and questions about the Identity of a body are very often questions about words. But Identity, when applied to persons, has no ambiguity, and admits not of degrees, or of more

or less. It is the foundation of all rights and obligations, and of all. accountableness; and the notion of it is fixed and precise.

OF THE TRAIN OF THOUGHT IN THE MIND.

405. EVERY man is conscious of a Succession of Thoughts which pass in his mind while he is awake, even when they are not excited by external objects.

Obs. The mind on this account has been compared to liquor in the state of fermentation. When it is not in this state, being once at rest, it remains at rest, until it is moved by some external impulse or internal prompter. But, in the state of fermentation, it has some cause of motion in itself, which, even when there is no impulse from without, suffers it not to be at rest a moment, but produces a constant motion and ebullition, while it continues to ferment.

406. There is surely no similitude between motion and Thought; but there is an analogy, so obvious to all men, that the same words are often applied to both; and many modifications of Thought have no name but such as is borrowed from the modifications of motion. (See Art. 223 and 238. Illus. 1 and 2.)

Obs. 1. Many Thoughts are excited by the senses. The causes or occasions of these may be considered as external; but, when such external causes do not operate upon us, we continue to think from some internal cause. From the constitution of the mind itself there is a constant ebullition of Thought, a constant intestine motion; not only of Thoughts barely speculative, but of sentiments, passions, and affections, which attend them. (See Art. 224. Illus.)

2. This continued succession of thought has, by some philosophers, been called the imagination. It was formerly called the fancy, or the phantasy. If the old name be laid aside, it were to be wished that a name were given to it less ambiguous than that of Imagination,—a name which has two or three meanings besides. (Art. 259. Obs. 1 and 2, and Art. 141.)

3. It is often called the train of ideas. This may lead one to think, that it is a train of bare conceptions; but this would surely be a mistake. It is made up of many other operations of mind, as well as of conceptions, or ideas. (Art. 200.)

Example. Memory, judgment, reasoning, passions, affections, and purposes; in a word, every operation of the mind (excepting those of sense) is exerted occasionally in this Train of Thought, and has its share as an ingredient; so that we must take the word idea in a