the purpose as well as the Greek word idea; with this advantage, that they are less ambiguous. There is, indeed, a meaning of the word idea, which I think most agreeable to its use in ancient philosophy, and which I would willingly adopt, if use, the arbiter of language, did permit. But this will come to be explained afterwards.

11. The word impression is used by Mr. Hume, in speaking of the operations of the mind, almost as often as the word idea is by Mr. Locke. What the latter calls ideas, the former divides into two classes; one of which he calls impressions, the other ideas. I shall make some observations upon Mr. Hume's explication of that word, and then consider the proper meaning of it in the English language.

"We may divide (says Mr. Hume, Essays, vol. ii. p. 18) all the perceptions of the human mind into two classes or species, which are distinguished by their different degrees of force and vivacity. The less lively and forcible are commonly denominated thoughts or ideas. The other species want a name in our language, and in most others; let us therefore use a little freedom, and call them impressions. By the term impressions, then, I mean all our more lively perceptions, when we hear, or see, or feel, or love, or hate, or desire, or will.. Ideas are the less lively perceptions, of which we are conscious, when we reflect on any of those sensations or movements above mentioned."

This is the explication Mr. Hume hath given in his Essays of the term impressions, when applied to the mind; and his explication of it, in his Treatise of Human Nature, is to the same purpose.

Disputes about words belong rather to grammarians than to philosophers; but philosophers ought not to escape censure when they corrupt a language, by using words in a way which the purity of the language will not admit. I find fault with Mr. Hume's phraseology in the words I have quoted.

First, Because he gives the name of perceptions to every operation of the mind. Love is a perception, hatred a perception. Desire is a perception, will is a perception; and, by the same rule, a doubt, a question, a command, is a perception. This is an intolerable abuse of language, which no philosopher has authority to introduce.

Secondly, When Mr. Hume says, that we may divide all the perceptions of the human mind into two classes or species, which are distinguished by their degrees of force and vivacity, the manner of expression is loose and unphilosophical. To differ in species is one thing; to differ in degree is another. Things which differ in degree only must be of the same species. It is a maxim of common sense, admitted by all men, that greater and less do not make a change of species. The same man may differ in the degree of his force and vivacity, in the morning and at night; in health and in sickness: but this is so far from making him a different species, that it does not so much as make him a different individual. To say, therefore, that two different classes or species of perceptions are distinguished by the degrees of their force and vivacity, is to confound a difference of degree with a difference of species, which every man of understanding knows how to distinguish.

Thirdly, We may observe, that this author, having given the general name of perception to all the operations of the mind, and distinguished them into two classes or species, which differ only in degree of force and vivacity, tells us, that he gives the name of impressions to all our more lively perceptions; to wit, when we hear, or see, or feel, or love, or hate, or desire, or will. There is great confusion in this account of the meaning of the word impression. When I see, this is an impression. But why

has not the Author told us, whether he gives the name of impression to the object seen, or to that act of my mind by which I see it? When I see the full moon, the full moon is one thing, my perceiving it is another thing. Which of these two things does he call an impression? We are left to guess this; nor does all that this Author writes about impressions clear this point. Every thing he says tends to darken it, and to lead us to think, that the full moon which I see, and my seeing it, are not two things, but one and the same thing.

The same observation may be applied to every other instance the Author gives to illustrate the meaning of the word impression. "When we hear, when we feel, when we love, when we hate, when we desire, when we will." In all these acts of the mind there must be an object, which is heard or felt, or loved or hated, or desired or willed. Thus, for instance, I love my country. This, says Mr. Hume, is an impression. But what is the impression? Is it my country, or is it the affection I bear to it? I ask the Philosopher this question; but I find no answer to it. And when I read all that he has written on this subject, I find this word impression sometimes used to signify an operation of the mind, sometimes the object of the operation; but for the most part, it is a vague and indetermined word that signifies both.

I know not whether it may be considered as an apology for such abuse of words, in an Author who understood the language so well, and used it with so great propriety in writing on other subjects, that Mr. Hume's system with regard to the mind required a language of a different structure from the common; or, if expressed in plain English, would have been too shocking to the common sense of mankind. To give an instance or two of this. If a man receive a present on which he puts a high value; if he see and handle it, and put it in his pocket, this, says Mr. Hume, is an impression. If the man only dream that he received such a present, this is an idea. Wherein lies the difference between this impression and this idea; between the dream and the reality? They are different classes or species, says Mr. Hume: so far all men will agree with him. But he adds, that they are distinguished only by different degrees of force and vivacity. Here he insinuates a tenet of his own, in contradiction to the common sense of mankind. Common sense convinces every man that a lively dream is no nearer to a reality than a faint one; and that if a man should dream that he had all the wealth of Croesus, it would not put one farthing in his pocket. It is impossible to fabricate arguments against such undeniable principles, without confounding the meaning of words.

In like manner, if a man would persuade me that the moon which I see, and my seeing it, are not two things, but one and the same thing, he will answer his purpose less by arguing this point in plain English, than by confounding the two under one name, such as that of an impression: for such is the power of words, that if we can be brought to the habit of calling two things, that are connected, by the same name, we are the more easily led to believe them to be one and the same thing.

Let us next consider the proper meaning of the word impression in English, that we may see how far it is fit to express either the operations of the mind or their objects.

When a figure is stamped upon a body by pressure, that figure is called an impression, as the impression of a seal on wax, of printing types, or of a copperplate on paper. This seems now to be the literal sense of the word; the effect borrowing its name from the cause. But by metaphor or analogy, like most other words, its meaning is extended, so as to signify any change

produced in a body by the operation of some external cause.

A blow of

the hand makes no impression on a stone-wall; but a battery of cannon may. The moon raises a tide in the ocean, but makes no impression on rivers and lakes.

When we speak of making an impression on the mind, the word is carried still farther from its literal meaning; use, however, which is the arbiter of language, authorises this application of it. As when we say that admonition and reproof make little impression on those who are confirmed in bad habits. The same discourse delivered in one way, makes a strong impression on the hearers; delivered in another way, it makes no impression at all.

It may be observed, that in such examples, an impression made on the mind always implies some change of purpose or will; some new habit produced, or some former habit weakened; some passion raised or allayed. When such changes are produced by persuasion, example, or any external cause, we say that such causes make an impression upon the mind. But when things are seen or heard, or apprehended, without producing any passion or emotion, we say that they make no impression.

In the most extensive sense, an impression is a change produced in some passive subject by the operation of an external cause. If we suppose an active being to produce any change in itself by its own active power, this is never called an impression. It is the act or operation of the being itself, not an impression upon it From this it appears, that to give the name of an impression to any effect produced in the mind, is to suppose that the mind does not act at all in the production of that effect. If seeing, hearing, desiring, willing, be operations of the mind, they cannot be impressions. If they be impressions, they cannot be operations of the mind. In the structure of all languages, they are considered as acts or operations of the mind itself, and the names given them imply this. call them impressions, therefore, is to trespass against the structure, not of a particular language only, but of all languages.

То

If the word impression be an improper word to signify the operations of the mind, it is at least as improper to signify their objects; for would any man be thought to speak with propriety, who should say that the sun is an impression, that the earth and the sea are impressions?

It is commonly believed, and taken for granted, that every language, if it be sufficiently copious in words, is equally fit to express all opinions, whether they be true or false. I apprehend, however, that there is an exception to this general rule, which deserves our notice. There are certain common opinions of mankind, upon which the structure and grammar of all languages are founded. While these opinions are common to all men, there will be a great similarity in all languages that are to be found on the face of the earth. Such a similarity there really is; for we find in all languages the same parts of speech, the distinction of nouns and verbs, the distinction of nouns into adjective and substantive, of verbs into active and passive. In verbs we find like tenses, moods, persons, and numbers. There are general rules of grammar, the same in all languages. This similarity of structure in all languages shows an uniformity among men in those opinions upon which the structure of language is founded.

If, for instance, we should suppose that there was a nation who believed that the things which we call attributes might exist without a subject, there would be in their language no distinction between adjectives and substantives, nor would it be a rule with them, that an adjective has no meaning unless when joined to a substantive. If there was any nation who

did not distinguish between acting and being acted upon, there would in their language be no distinction between active and passive verbs, nor would it be a rule that the active verb must have an agent in the nominative case; but that, in the passive verb, the agent must be in an oblique case.

The structure of all languages is grounded upon common notions, which Mr. Hume's philosophy opposes, and endeavours to overturn. This no doubt led him to warp the common language into a conformity with his principles; but we ought not to imitate him in this, until we are satisfied that his principles are built on a solid foundation.

12. Sensation is a name given by philosophers to an act of mind, which may be distinguished from all others by this, that it hath no object distinct from the act itself. Pain of every kind is an uneasy sensation. When I am pained, I cannot say, that the pain I feel is one thing, and that my feeling it is another thing. They are one and the same thing, and cannot be disjoined even in imagination. Pain, when it is not felt, has no existence. It can be neither greater nor less in degree or duration, nor any thing else in kind, than it is felt to be. It cannot exist by itself, nor in any subject, but in a sentient being. No quality of an inanimate and sentient being can have the least resemblance to it.

What we have said of pain may be applied to every other sensation. Some of them are agreeable, others uneasy, in various degrees. These being objects of desire or aversion, have some attention given to them; but many are indifferent, and so little attended to, that they have no name in any language.

Most operations of the mind, that have names in common language, are complex in their nature, and made up of various ingredients, or more simple acts; which, though conjoined in our constitution, must be disjoined by abstraction, in order to our having a distinct and scientific notion of the complex operation. In such operations, sensation for the most part makes an ingredient. Those who do not attend to the complex nature of such operations are apt to resolve them into some one of the simple acts of which they are compounded, overlooking the others: and from this cause many disputes have been raised, and many errors have been occasioned with regard to the nature of such operations.

The perception of external objects is accompanied with some sensation corresponding to the object perceived, and such sensations have, in many cases, in all languages, the same name with the external object which they always accompany. The difficulty of disjoining by abstraction things thus constantly conjoined in the course of nature, and things which have one and the same name in all languages, has likewise been frequently an occasion of errors in the philosophy of the mind. To avoid such errors, nothing is of more importance than to have a distinct notion of that simple act of the mind which we call sensation, and which we have endeavoured to describe. By this means we shall find it more easy to distinguish it from every external object that it accompanies, and from every other act of the mind that may be conjoined with it. For this purpose it is likewise of importance that the name of sensation should, in philosophical writings, be appropriated to signify this simple act of the mind, without including any thing more in its signification, or being applied to other purposes.

I shall add an observation concerning the word feeling. This word has two meanings. First, It signifies the perceptions we have of external objects, by the sense of touch. When we speak of feeling a body to be hard or soft, rough or smooth, hot or cold; to feel these things, is to

perceive them by touch. They are external things, and that act of the mind by which we feel them, is easily distinguished from the objects felt: Secondly, The word feeling is used to signify the same thing as sensation, which we have just now explained; and, in this sense, it has no object; the feeling and the thing felt are one and the same.

Perhaps betwixt feeling taken in this last sense, and sensation, there may be this small difference, that sensation is most commonly used to signify those feelings which we have by our external senses and bodily appetites, and all our bodily pains and pleasures. But there are feelings of a nobler nature accompanying our affections, our moral judgments, and our determinations in matters of taste, to which the word sensation is less properly applied.

I have premised these observations on the meaning of certain words that frequently occur in treating of this subject, for two reasons, first, That I may be the better understood when I use them; and, secondly, That those who would make any progress in this branch of science may accustom themselves to attend very carefully to the meaning of words that are used in it. They may be assured of this, that the ambiguity of words, and the vague and improper application of them, have thrown more darkness upon this subject, than the subtilty and intricacy of things.

When we use common words, we ought to use them in the sense in which they are most commonly used by the best and purest writers in the language; and, when we have occasion to enlarge or restrict the meaning of a common word, or give it more precision than it has in common language, the reader ought to have warning of this, otherwise we shall impose upon ourselves and upon him.

A very respectable writer has given a good example of this kind, by explaining, in an Appendix to his Elements of Criticism, the terms he has occasion to use. In that Appendix, most of the words are explained on which I have been making observations. And the explication I have given, I think, agrees, for the most part, with his.

Other words that need explication shall be explained as they occur.

CHAPTER II.

PRINCIPLES TAKEN FOR GRANTED.

As there are words common to Philosophers and to the vulgar, which need no explication, so there are principles common to both which need no proof, and which do not admit of direct proof.

One who applies to any branch of science must be come to years of understanding, and consequently must have exercised his reason, and the other powers of his mind, in various ways. He must have formed various opinions and principles, by which he conducts himself in the affairs of life. Of those principles, some are common to all men, being evident in themselves, and so necessary in the conduct of life, that a man cannot live and act according to the rules of common prudence without them.

All men that have common understanding agree in such principles, and consider a man as lunatic, or destitute of common sense, who denies or calls them in question. Thus, if any man were found of so strange a turn as not to believe his own eyes; to put no trust in his senses, nor have the least regard to their testimony; would any man think it worth while to reason gravely with such a person, and, by argument, to convince him of