his error? Surely no wise man would. For before men can reason together, they must agree in first principles; and it is impossible to reason with a man who has no principles in common with you.

There are, therefore, common principles, which are the foundation of all reasoning, and of all science. Such common principles seldom admit of direct proof, nor do they need it. Men need not to be taught them; for they are such as all men of common understanding know; or such, at least, as they give a ready assent to, as soon as they are proposed and understood. Such principles, when we have occasion to use them in science, are called axioms. And, although it be not absolutely necessary, yet it may be of great use, to point out the principles or axioms on which a science is grounded.

Thus, mathematicians, before they prove any of the propositions of mathematics, lay down certain axioms, or common principles, upon which they build their reasonings. And although those axioms be truths which every man knew before, such as, That the whole is greater than a part, That equal quantities added to equal quantities make equal sums; yet, when we see nothing assumed in the proof of mathematical propositions but such self-evident axioms, the propositions appear more certain, and leave no room for doubt or dispute.

In all other sciences, as well as in mathematics, it will be found, that there are a few common principles, upon which all the reasonings in that science are grounded, and into which they may be resolved. If these were pointed out and considered, we should be better able to judge what stress may be laid upon the conclusions in that science. If the principles be certain, the conclusions justly drawn from them must be certain. If the principles be only probable, the conclusions can only be probable. If the principles be false, dubious, or obscure, the superstructure that is built upon them must partake of the weakness of the foundation.

Sir Isaac Newton, the greatest of natural philosophers, has given an example well worthy of imitation, by laying down the common principles or axioms on which the reasonings in natural philosophy are built. Before this was done, the reasonings of philosophers, in that science, were as vague and uncertain as they are in most others. Nothing was fixed; all was dispute and controversy: but, by this happy expedient, a solid foundation is laid in that science, and a noble superstructure is raised upon it, about which there is now no more dispute or controversy among men of knowledge, than there is about the conclusions of mathematics.

It may, however, be observed, that the first principles of natural philosophy are of a quite different nature from mathematical axioms: they have not the same kind of evidence, nor are they necessary truths, as mathematical axioms are: they are such as these; that similar effects proceed from the same or similar causes; that we ought to admit of no other causes of natural effects, but such as are true, and sufficient to account for the effects. These are principles, which, though they have not the same kind of evidence that mathematical axioms have: yet have such evidence, that every man of common understanding readily assents to them, and finds it absolutely necessary to conduct his actions and opinions by them in the ordinary affairs of life.

Though it has not been usual, yet I conceive it may be useful, to point out some of those things which I shall take for granted, as first principles, in treating of the mind and its faculties. There is the more occasion for this; because very ingenious men, such as Des Cartes, Malebranche, Arnauld, Locke, and many others, have lost much labour by not distinguishing

things which require proof, from things which, though they may admit of illustration, yet being self-evident, do not admit of proof. When men attempt to deduce such self-evident principles from others more evident, they always fall into inconclusive reasoning: And the consequence of this has been, that others, such as Berkeley and Hume, finding the arguments brought to prove such first principles to be weak and inconclusive, have been tempted first to doubt of them, and afterwards to deny them.

It is so irksome to reason with those who deny first principles, that wise men commonly decline it. Yet it is not impossible, that what is only a vulgar prejudice may be mistaken for a first principle. Nor is it impossible, that what is really a first principle may, by the enchantment of words, have such a mist thrown about it, as to hide its evidence, and to make a man of candour doubt of it. Such cases happen more frequently perhaps in this science than in any other; but they are not altogether without remedy. There are ways by which the evidence of first principles may be made more apparent when they are brought into dispute; but they require to be handled in a way peculiar to themselves. Their evidence is not demonstrative, but intuitive. They require not proof, but to be placed in a proper point of view. This will be shown more fully in its proper place, and applied to those very principles which we now assume. In the mean time, when they are proposed as first principles, the reader is put on his guard, and warned to consider whether they have a just claim to that cha

racter.

1. First, then, I shall take it for granted, that I think, that I remember, that I reason, and, in general, that I really perform all those operations of mind of which I am conscious.

The operations of our minds are attended with consciousness; and this consciousness is the evidence, the only evidence which we have or can have of their existence. If a man should take it into his head to think or to say that his consciousness may deceive him, and to require proof that it cannot, I know of no proof that can be given him; he must be left to himself as a man that denies first principles, without which there can be no reasoning. Every man finds himself under a necessity of believing what consciousness testifies, and every thing that hath this testimony is to be taken as a first principle.

2. As by consciousness we know certainly the existence of our present thoughts and passions; so we know the past by remembrance. And when they are recent, and the remembrance of them fresh, the knowledge of them, from such distinct remembrance, is, in its certainty and evidence, next to that of consciousness.

3. But it is to be observed, that we are conscious of many things to which we give little or no attention. We can hardly attend to several things at the same time; and our attention is commonly employed about that which is the object of our thought, and rarely about the thought itself. Thus, when a man is angry, his attention is turned to the injury done him, or the injurious person; and he gives very little attention to the passion of anger, although he is conscious of it. It is in our power, however, when we come to the years of understanding, to give attention to our own thoughts and passions, and the various operations of our minds. And when we make these the objects of our attention, either while they are present, or when they are recent and fresh in our memory, this act of the mind is called reflection.

We take it for granted, therefore, that, by attentive reflection, a man may have a clear and certain knowledge of the operations of his own mind;

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a knowledge no less clear and certain, than that which he has of an external object when it is set before his eyes.

This reflection is a kind of intuition; it gives a like conviction with regard to internal objects, or things in the mind, as the faculty of seeing gives with regard to objects of sight. A man must, therefore, be convinced beyond possibility of doubt, of every thing with regard to the operations of his own mind, which he clearly and distinctly discerns by attentive reflection.

4. I take it for granted, that all the thoughts I am conscious of, or remember, are the thoughts of one and the same thinking principle, which I call myself, or my mind. Every man has an immediate and irresistible conviction, not only of his present existence, but of his continued existence and identity, as far back as he can remember. If any man should think fit to demand a proof that the thoughts he is successively conscious of belong to one and the same thinking principle; if he should demand a proof that he is the same person to-day as he was yesterday, or a year ago, I know no proof that can be given him: He must be left to himself, either as a man that is lunatic, or as one who denies first principles, and is not to be reasoned with.

Every man of a sound mind finds himself under the necessity of believing his own identity, and continued existence. The conviction of this is immediate and irresistible; and if he should lose this conviction, it would be a certain proof of insanity, which is not to be remedied by reasoning.

5. I take it for granted, that there are some things which cannot exist by themselves, but must be in something else to which they belong, as qualities, or attributes.

And to

Thus, motion cannot exist but in something that is moved. suppose that there can be motion while every thing is at rest, is a gross and palpable absurdity. In like manner, hardness and softness, sweetness and bitterness, are things which cannot exist by themselves; they are qualities of something which is hard or soft, sweet or bitter: That thing. whatever it be, of which they are qualities, is called their subject, and such qualities necessarily suppose a subject.

Things which may exist by themselves, and do not necessarily suppose the existence of any thing else, are called substances; and with relation to the qualities or attributes that belong to them, they are called the subjects of such qualities or attributes.

All the things which we immediately perceive by our senses, and all the things we are conscious of, are things which must be in something else as their subject. Thus by my senses I perceive figure, colour, hardness, softness, motion, resistance, and such like things. But these are qualities, and must necessarily be in something that is figured, coloured, hard or soft, that moves or resists. It is not to these qualities, but to that which is the subject of them, that we give the name of body. If any man should think fit to deny that these things are qualities, or that they require any subject, I leave him to enjoy his opinion as a man who denies first principles, and is not fit to be reasoned with. If he has common understanding, he will find that he cannot converse half an hour without saying things which imply the contrary of what he professes to believe.

In like manner, the things I am conscious of, such as thought, reasoning, desire, necessarily suppose something that thinks, that reasons, that desires. We do not give the name of mind to thought, reason, or desire; but to that being which thinks, which reasons, and which desires.

That every act or operation, therefore, supposes an agent, that every

quality supposes a subject, are things which I do not attempt to prove, but take for granted. Every man of common understanding discerns this immediately, and cannot entertain the least doubt of it. In all languages we find certain words which, by grammarians, are called adjectives. Such words denote attributes, and every adjective must have a substantive to which it belongs; that is, every attribute must have a subject. In all languages we find active verbs, which denote some action or operation; and it is a fundamental rule in the grammar of all languages, that such a verb supposes a person; that is, in other words, that every action must have an agent. We take it, therefore, as a first principle, that goodness, wisdom, and virtue can only be in some being that is good, wise, and virtuous; that thinking supposes a being that thinks; and that every operation we are conscious of supposes an agent that operates, which we call mind.

6. I take it for granted, that in most operations of the mind, there must be an object distinct from the operation itself. I cannot see, without seeing something. To see without having any object of sight is absurd. I cannot remember, without remembering something. The thing remembered is past, while the remembrance of it is present: and therefore the operation and the object of it must be distinct things. The operations of our minds are denoted, in all languages, by active transitive verbs, which, from their construction in grammar, require not only a person or agent, but likewise an object of the operation. Thus the verb know, denotes an operation of mind. From the general structure of language, this verb requires a person; I know, you know, or he knows: But it requires no less a noun in the accusative case, denoting the thing known; for he that knows must know something; and to know, without having any object of knowledge, is an absurdity too gross to admit of reasoning.

7. We ought likewise to take for granted, as first principles, things wherein we find an universal agreement, among the learned and unlearned, in the different nations and ages of the world. A consent of ages and nations, of the learned and vulgar, ought, at least, to have great authority, unless we can show some prejudice, as universal as that consent is, which might be the cause of it. Truth is one, but error is infinite. There are many truths so obvious to the human faculties, that it may be expected that men should universally agree in them. And this is actually found to be the case with regard to many truths, against which we find no dissent, unless perhaps that of a few sceptical philosophers, who may justly be suspected, in such cases, to differ from the rest of mankind, through pride, obstinacy, or some favourite passion. Where there is such universal consent in things not deep nor intricate, but which lie, as it were, on the surface, there is the greatest presumption that can be, that it is the natural result of the human faculties, and it must have great authority with every sober mind that loves truth. Major enim pars eo fere deferri solet quo a natura deducitur. Cic. de Off. I. 41.

Perhaps it may be thought, that it is impossible to collect the opinions of all men upon any point whatsoever, and, therefore, that this maxim can be of no use. But there are many cases wherein it is otherwise. Who can doubt, for instance, whether mankind have, in all ages, believed the existence of a material world, and that those things which they see and handle are real, and not mere illusions and apparitions? Who can doubt, whether mankind have universally believed, that every thing that begins to exist, and every change that happens in nature, must have a cause? Who can doubt, whether mankind have been universally persuaded that

there is a right and a wrong in human conduct? Some things which, in certain circumstances, they ought to do, and other things which they ought not to do? The universality of these opinions, and of many such that might be named, is sufficiently evident, from the whole tenor of men's conduct, as far as our acquaintance reaches, and from the records of history, in all ages and nations, that are transmitted to us.

There are other opinions that appear to be universal, from what is common in the structure of all languages, ancient and modern, polished and barbarous. Language is the express image and picture of human thoughts; and from the picture, we may often draw very certain conclusions with regard to the original. We find in all languages the same parts of speech, nouns substantive and adjective, verbs active and passive, varied according to the tenses of past, present, and future; we find adverbs, prepositions, and conjunctions. There are general rules of syntax common to all languages. This uniformity in the structure of language shows a certain degree of uniformity in those notions upon which the structure of language is grounded.

We find, in the structure of all languages, the distinction of acting and being acted upon, the distinction of action and agent, of quality and subject, and many others of the like kind; which shows, that these distinctions are founded in the universal sense of mankind. We shall have frequent occasion to argue from the sense of mankind expressed in the structure of language; and therefore it was proper here to take notice of the force of arguments drawn from this topic.

8. I need hardly say, that I shall also take for granted such facts as are attested to the conviction of all sober and reasonable men, either by our senses, by memory, or by human testimony. Although some writers on this subject have disputed the authority of the senses, of memory, and of every human faculty; yet we find, that such persons, in the conduct of life, in pursuing their ends, or in avoiding dangers, pay the same regard to the authority of their senses and other faculties, as the rest of mankind. By this they give us just ground to doubt of their candour in their professions of scepticism.

This, indeed, has always been the fate of the few that have professed scepticism, that when they have done what they can to discredit their senses, they find themselves, after all, under a necessity of trusting to them. Mr. Hume has been so candid as to acknowledge this; and it is no less true of those who have not shown the same candour: For I never heard that any sceptic ran his head against a post, or stept into a kennel, because he did not believe his eyes.

Upon the whole, I acknowledge that we ought to be cautious, that we do not adopt opinions as first principles, which are not entitled to that character. But there is surely the least danger of men's being imposed upon in this way, when such principles openly lay claim to the character, and are thereby fairly exposed to the examination of those who may dispute their authority. We do not pretend, that those things that are laid down as first principles may not be examined, and that we ought not to have our ears open to what may be pleaded against their being admitted as such. Let us deal with them as an upright judge does with a witness who has a fair character. He pays a regard to the testimony of such a witness, while his character is unimpeached. But if it can be shown that he is suborned, or that he is influenced by malice or partial favour, his testimony loses all its credit, and is justly rejected.