Arguments from analogy are always at hand, and grow up spontaneously in a fruitful imagination, while arguments that are more direct and more conclusive often require painful attention and application: and therefore mankind in general have been very much disposed to trust to the former. If one attentively examines the systems of the ancient philosophers, either concerning the material world, or concerning the mind, he will find them to be built solely upon the foundation of analogy. Lord Bacon first de- lineated the strict and severe method of induction; since his time it has been applied with very happy success in 246 OF THE HUMAN MIND.
some parts of natural philosophy; and hardly in any thing else. But there is no subject in which mankind are so much disposed to trust to the analogical way of thinking and reasoning, as in what concerns the mind and its ope- rations; because, to form clear and distinct notions of those operations in the direct and proper way, and to reason about them, requires a habit of attentive reflection, of which few are capable, and which, even by those few, cannot be attained without much pains and labour.
Every man is apt to form his notions of things difficult to be apprehended, or less familiar, from their analogy to things which are more familiar. Thus, if a man bred to the seafaring life, and accustomed to think and talk only of matters relating to navigation, enters into discourse upon any other subject; it is well known that the language and the notions proper to his own profession are infused into every subject, and all things are measured by the rules of navigation: and if he should take it into his head to phi- losophize concerning the faculties of the mind, it cannot be doubted but he would draw his notions from the fabric of his ship, and would find in the mind, sails, masts, rudder, and compass.
Sensible objects of one kind or other do no less occupy and engross the rest of mankind than things relating to na- vigation the seafaring man. For a considerable part of life we can think of nothing but the objects of sense; and to attend to objects of another nature, so as to form clear and distinct notions of them, is no easy matter, even after we come to years of reflection. The condition of man- kind, therefore, affords good reason to apprehend, that their language and their common notions concerning the mind and its operations will be analogical, and derived from the objects of sense; and that these analogies will be apt to impose upon philosophers as well as upon the vulgar, and to lead them to materialize the mind and its faculties; and experience abundantly confirms the truth of this.
How generally men of all nations and in all ages of the world have conceived the soul, or thinking principle in CHAP. VII.] CONCLUSION. 247 man, to be some subtile matter, like breath or wind, the names given to it in almost all languages sufficiently testify. We have words which are proper, and not analogical, to express the various ways in which we perceive external objects by the senses; such as feeling ^ sight, taste: but we are often obliged to use these words analogically, to express other powers of the mind which are of a very dif- ferent nature. And the powers which imply some degree of reflection have generally no names but such as are ana- logical. The objects of thought are said to be in the mind, to be apprehended, comprehended, conceived, ima- gined, retained, weighed, ruminated.
It does not appear that the notions of the ancient philo- sophers, with regard to the nature of the soul, were much more refined than those of the vulgar, or that they were formed in any other way. We shall distinguish the phi- losophy that regards our subject into the old and the new. The old reached down to Des Cartes, who gave it a fatal blow, of which it has been gradually expiring ever since, and is now almost extinct. Des Cartes is the father of the new philosophy that relates to this subject; but it hath been gradually improving since his time upon the prin- ciples laid down by him. The old philosophy seems to have been purely analogical: the new is more derived from reflection, but still with a very considerable mixture of the old analogical notions.
Because the objects of sense consist of matter and form, the ancient philosophers conceived every thing to belong to one of these, or to be made up of both. Some therefore thought that the soul is a particular kind of subtile matter separable from our gross bodies; others thought that it is only a particular form of the body, and inseparable from it. For there seem to have been some among the ancients as well as among the moderns, who conceived that a certain structure or organization of the body is all that is necessary to render it sensible and in- telligent. The different powers of the mind were, accord- ingly, by the last sect of philosophers, conceived to be- long to different parts of the body, as the heart, the brain, the liver, the stomach, the blood.
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They who thought that the soul is a subtile matter, se- parable from the body, disputed to which of the four ele- ments it belongs, whether to earth, water, air, or fire. Of the three last each had its particular advocates. But some were of opinion that it partakes of all the "elements; that it must have something in its composition similar to every thing we perceive; and that we perceive earth by the earthly part; water by the watery part; and fire by the fiery part of the soul. Some philosophers, not satisfied with determin- ing of what kind of matter the soul is made, inquired like- wise into its figure, which they determined to be spherical, that it might be the more fit for motion. The most spiri- tual and sublime notion concerning the nature of the soul, to be met with among the ancient philosophers, I conceive to be that of the Platonists, who held that it is made of that celestial and incorruptible matter of which the fixed stars were made, and therefore has a natural tendency to rejoin its proper element. I am at a loss to say in which of these classes of philosophers Aristotle ought to be placed. He defines the soul to be, The first evreKe^etct of a natural body which has potential life. I beg to be excused from translating the Greek word, because I know not the meaning of it.
The notions of the ancient philosophers with regard to the operations of the mind, particularly with regard to per- ceptions and ideas, seem likewise to have been formed by the same kind of analogy.
Plato, of the writers that are extant, first introduced the word idea into philosophy; but his doctrine upon this subject had somewhat peculiar. He agreed with the rest of the ancient philosophers in this, that all things consist of matter and form; and that the matter of which all things were made existed from eternity without form; but he likewise believed that there are eternal forms of all possible things which exist without matter; and to these eternal and immaterial forms he gave the name of ideas; maintaining that they are the only object of true knowledge. It is of no great moment to us whether he borrowed these notions from Parnienides, or whether they CHAP. VII.] CONCLUSION. 249 were the issue of his own creative imagination. The latter Platonists seem to have improved upon them, in conceiving those ideas, or eternal forms of things to exist, not of them- selves, but in the Divine Mind, and to be the models and patterns according to which all things were made: Then lived the Eternal One, then, deep retired In his unfathom'd essence, viewed at large The uncreated images of things.
To these Platonic notions, that of Malebranche is very nearly allied. This author seems more than any other to have been aware of the difficulties attending the common hypothesis concerning ideas, to wit, That ideas of all ob- jects of thought are in the human mind; and therefore, in order to avoid those difficulties, makes the ideas which are the immediate objects of human thought to be the ideas of things in the Divine Mind; who being intimately present to every human mind, may discover his ideas to it, as far as pleaseth him.
The Platonists and Malebranche excepted, all other philosophers, as far as I know, have conceived that there are ideas or images of every object of thought in the human mind, or at least in some part of the brain, where the mind is supposed to have its residence.
Aristotle had no good affection to the word idea, and seldom or ne-er uses it but hi refuting Plato's notions about ideas. He thought that matter may exist with- out form; but that form cannot exist without matter. But at the same time he taught, That there can be no sensa- tion, no imagination, nor intellection, without forms, phan- tasms, or species in the mind; and that things sensible are perceived by sensible species, and things intelligible by intelligible species. His followers taught more explicitly, that those sensible and intelligible species are sent forth by the objects, and make their impressions upon the passive intellect; and that the active intellect perceives them in the passive intellect. And this seems to have been the common opinion while the Peripatetic philosophy retained its authority.
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The Epicurean doctrine, as explained by Lucretius, though widely different from the Peripatetic in many things, is almost the same in this. He affirms that slen- der films or ghosts (tenuia rerum simulacra) are still going off from all things and flying about; and that these being extremely subtile, easily penetrate our gross bodies, and striking upon the mind, cause thought and imagi- nation.
After the Peripatetic system had reigned above a thou- sand years in the schools of Europe, almost without a rival, it sunk before that of Des Cartes; the perspicuity of whose writings and notions, contrasted with the obscu- rity of Aristotle and his commentators, created a strong prejudice in favour of this new philosophy. The charac- teristic of Plato's genius was sublimity, that of Aristotle's subtlety: but Des Cartes far excelled both in perspicuity, and bequeathed this spirit to his successors. The system which is now generally received, with regard to the mind and its operations, derives not only its spirit from Des Cartes, but its fundamental principles; and after all the improvements made by Malebranche, Locke, Berkeley, and Hume, may still be called the Cartesian system: we shall therefore make some remarks upon its spirit and ten- dency in general, and upon its doctrine concerning ideas in particular.
It may be observed, That the method which Des Cartes pursued, naturally led him to attend more to the operations of the mind by accurate reflection, and to trust less to ana- logical reasoning upon this subject, than any philosopher had done before him. Intending to build a system upon a new foundation, he began with a resolution to admit nothing but what was absolutely certain and evident. He supposed that his senses, his memoiy, his reason, and every other faculty to which we trust in common life, might be fallacious; and resolved to disbelieve every thing until he was compelled by irresistible evidence to yield assent.
In this method of proceeding, what appeared to him first of all certain and evident, was, That he thought, that CHAP. VII.] CONCLUSION. 251 he doubted, that he deliberated. In a word, the operations of his own mind, of which he was conscious, must be real, and no delusion; and though all his other faculties should deceive him, his consciousness could not. This therefore he looked upon as the first of all truths. This was the first firm ground upon which he set his foot after being- tossed in the ocean of scepticism; and he resolved to build all knowledge upon it, without seeking after any more first principles.
As every other truth, therefore, and particularly the existence of the objects of sense, was to be deduced by a train of strict argumentation from what he knew by consci- ousness, he was naturally led to give attention to the ope- rations of which he was conscious, without borrowing his notions of them from external things.
It was not in the way of analogy, but of attentive reflec- tion, that he was led to observe, That thought, volition, remembrance, and the other attributes of the mind, are altogether unlike to extension, to figure, and to all the attributes of body; that we have no reason, therefore, to conceive thinking substances to have any resemblance to extended substances; and that, as the attributes of the thinking substance are things of which we are conscious we may have a more certain and immediate knowledge of them by reflection, than we can have of external objects by our senses.
These observations, as far as I know, were first made by Des Cartes, and they are of more importance, and throw more light upon the subject than all that had been said upon it before. They ought to make us diffident and jealous of every notion concerning the mind and its "Operations, which is drawn from sensible objects in the way of analogy, and to make us rely only upon accurate reflection, as the source of all real knowledge upon this subject.
2. I observe, that as the Peripatetic system has a ten- dency to materialize the mind and its operations; so the Cartesian has a tendency to spiritualize body and its qua- lities. One error, common to both systems, leads to the first of these extremes in the way of analogy, and to the 252 OF THE HUMAN MIND.
last in the way of reflection. The error I mean is, That we can know nothing about body, or its qualities, but as far as we have sensations which resemble those qualities. Both systems agreed in this: but according to their dif- ferent methods of reasoning, they drew very different con- clusions from it; the Peripatetic drawing his notions of sensation from the qualities of body; the Cartesian, on the contrary, drawing his notions of the qualities of body from his sensations.
The Peripatetic, taking it for granted that bodies and their qualities do really exist, and are such as we com- monly take them to be, inferred from them-the nature of his sensations, and reasoned in this manner: our sensa- tions are the impressions which sensible objects make upon the mind, and may be compared to the impression of a seal upon wax; the impression is the image or form of the seal, without the matter of it: in like manner, every sen- sation is the image or form of some sensible quality of the object. This is the reasoning of Aristotle, and it has an evident tendency to materialize the mind and its sensa- tions.
The Cartesian, on the contrary, thinks that the existence of body, or of any of its qualities, is not to be taken as a first principle: and that we" ought to admit nothing con- cerning it, but what, by just reasoning, can be deduced from our sensations; and he knows that, by reflection, we can form 'clear and distinct notions of our sensations, with- out borrowing our notions of them by analogy from the objects of sense. The Cartesians, therefore, beginning to give attention to their sensations, first discovered that the sensations corresponding to secondary qualities cannot resemble any quality of body. Hence Des Cartes and Locke inferred, that sound, taste, smell, colour, heat, and cold, which'the vulgar took to be qualities of body, were not qualities of body, but mere sensations of the mind. Afterwards the ingenious Berkeley, considering more attentively the nature of sensation in general, discovered and demonstrated, that no sensation whatever could pos- sibly resemble any quality of an insentient being, such as CHAP. VII.] CONCLUSION. 2o3 body is supposed to be: and hence he inferred, very justly, that there is the same reason to hold extension, figure, and all the primary qualities, to be mere sensations, as there is to hold the secondary qualities to be mere sensations. Thus, by just reasoning upon the Cartesian principles, matter was stripped of all its qualities; the new system, by a kind of metaphysical sublimation, converted all the qua- lities of matter into sensations, and spiritualized body, as the old had materialized spirit.
The way to avoid both these extremes is, to admit the existence of what we see and feel as a first princip'n well as the existence of things whereof we are consci- ous; and to take our notions of the qualities of body, from the testimony of our senses with the Peripatetics; and our notions of our sensations, from the testimony of conscious- ness, with the Cartesians.
3. I observe, That the modern scepticism is the natural issue of the new system; and that, although it did not bring forth this monster until the year 1739, it may be said to have carried it in its womb from the beginning.
The old system admitted all the principles of common sense as first principles, without requiring any proof of them; and therefore, though its reasoning was commonly vague, analogical, and dark, yet it was built upon a broad foundation, and had no tendency to scepticism. We do not find that any Peripatetic thought it, incumbent upon him to prove the existence of a material world; but every writer upon the Cartesian system attempted this until Berkeley clearly demonstrated the futility of their argu- ments; and thence concluded, that there was no such thing as a material world; and that the belief of it ou°-ht to be rejected as a vulgar error.
The new system admits only one of the principles of common sense as a first principle; and pretends, by strict argumentation, to deduce all the rest from it. That our thoughts, our sensations, and every thing of which we are conscious, hath a real existence, is admitted in this system as a first principle; but every thing else must be made evident by the light of reason. Reason must rear the 254 OF THE HUMAN MIND.
whole fabric of knowledge upon this single principle of consciousness.
There is a disposition in human nature to reduce things to as few principles as possible; and this, without doubt, adds to the beauty of a system, if the principles are able to support what rests upon them. The mathematicians glory, very justly, in having raised so noble and magnifi- cent a system of science, upon the foundation of a few axioms and definitions. This love of simplicity of redu- cing things to few principles, hath produced many a false system; but there never was any system in which it ap- pears so remarkably as that of Des Cartes. His whole system concerning matter and spirit is built upon one axiom, expressed in one word, Cogito. Upon the foun- dation of conscious thought, with ideas for his materials, he builds his system of the human understanding, and attempts to account for all its phenomena: and having, as he imagined from his consciousness, proved the existence of matter, and of a certain quantity of motion originally impressed upon it, he builds his system of the material world, and attempts to account for all its phenomena.
These principles with regard to the material system have been found insufficient; and it has been made evident, that besides matter and motion we must admit gravitation, cohesion, corpuscular attraction, magnetism, and other centripetal and centrifugal forces, by which the particles of matter attract and repel each other. Newton having discovered this, and demonstrated that these principles cannot be resolved into matter and motion, was led by analogy and the love of simplicity to conjecture, but with a modesty and caution peculiar to him, that all the phe- nomena of the material world depended upon attracting and repelling forces in the particles of matter. But we may now venture to say, that this conjecture fell short of the mark. For even in the unorganized kingdom, the powers by which salts, crystal, spars, and many other bodies con- crete into regular forms, can never be accounted for by attracting and repelling forces in the particles of matter. And in the vegetable and animal kino-doms there are CHAP. VII.] CONCLUSION. 25 '» strong indications of powers of a different nature from all the powers of unorganized bodies. We see then, that although in the structure of the material world there is without doubt, all the beautiful simplicity consistent with the purposes for which it was made, it is not so simple as the great Des Cartes determined it to be: nay, it is not so simple as the greater Newton modestly conjectured it to be. Both were misled by analogy, and the love of sim- plicity. One hath been much conversant about extension, figure, and motion; the other had enlarged his views to attracting and repelling forces; and both formed their no- tions of the unknown parts of nature from those with which they were acquainted, as the shepherd Tityrus formed IIH notion of the city of Rome from his country village: Urbem, quam dicunt Romam, Melibcee, putavi Stultus ego hide nostrce similem, quo scepe solemus Pastores ovium teneros dcpellere foetus. Sic -canibus catulos similes, sic matribus hcedos Noram: sic parvis componere magna solebam.
This is a just picture of the analogical way of thinking.
But to come to the system of Des Cartes concerning the human understanding: it'was built, as we have observed, upon consciousness as its sole foundation, and with ideas as its materials; and all his followers have built upon the same foundation, and with the same materials. They ac- knowledge that nature hath given us various simple ideas: these are analogous to the matter of Des Cartes's physical system. They acknowledge likewise a natural power by which ideas are compounded, disjoined, associated, com- pared: this is analogous to the original quantity of motion in Des Cartes's physical system. From these principle they attempt to explain the phenomena of the human un- derstanding, just as in the physical system the phenomena of nature were to be explained by matter and motion. It must indeed be acknowledged that there is great simpli- city in this system as well as in the other. There is such a similitude between the two, as may be expected between children of the same father: but as the one has been found 256 OF THE HUMAN MIND.
to be the child of Des Cartes, and not of Nature, there is ground to think that the other is so likewise.
That the natural issue of this system is scepticism with regard to every thing except the existence of our ideas, and of their necessary relations which appear upon com- paring them, is evident: for ideas being the only objects of thought, and having no existence but when we are con- scious of them, it necessarily follows, that there is no ob- ject of our thought which can have a continued and per- manent existence. Body and spirit, cause and effect, time and space, to which we were wont to ascribe an ex- istence independent of our thought, are all turned out of existence by this short dilemma: either these things are ideas of sensation or reflection, or they are not: if they are ideas of sensation or reflection, they can have no exist- ence but when we are conscious of them; if they are not ideas of sensation or reflection, they are words without any meaning.
Neither Des Cartes nor Locke perceived this conse- quence of their system concerning ideas. Bishop Berke- ley was the first who discovered it. And what followed upon this discovery? Why, with regard to the material world, and with regard to space and time, he admits the consequence — That these things are mere ideas, and have no existence but in our minds: but with regard to the ex- istence of spirits or minds, he does not admit the conse- quence; and if he had admitted it, he must have been an absolute sceptic. But how does he evade this conse- quence with regard to the existence of spirits? The expe- dient which the good bishop uses on this occasion is veiy remarkable, and shows his great aversion to scepticism. He maintains that we have no ideas of spirits; and that we can think, and speak, and reason about them, and about their attributes, without having any ideas of them. If this is so, my lord, what should hinder us from thinking and reasoning about bodies and their qualities, without having ideas of them? The bishop either did not think of this question, or did not think fit to give any answer to it. However, we may observe, that in order to avoid seep- CHAP. VII.] CONCLUSION. 2-37 ticism, he fairly starts out of the Cartesian system, without giving any reason why he did so in this instance, and in no other. This indeed is the only instance of a deviation from Cartesian principles which I have met with in the successors of Des Cartes; and it seems to have been only a sudden start, occasioned by the terror of scepticism; for in all other things Berkeley's system is founded upon Car- tesian principles.
Thus we see, that Des Cartes and Locke take the road that leads to scepticism, without knowing the end of it; but they stop short for want of light to carry them farther. Berkeley, frighted at the appearance of the dreadful abyss, starts aside, and avoids it. But the author of the Treatise of Human Nature, more daring and intrepid, without turning aside to the right hand or to the left, like Virgil's Alecto, shoots directly into the gulf: Hie specus horrendum, et soevi spiracula Ditis Monstrantur: ruptoque ingens Acheronte voraga Pestiferas aper it fauces.
4. We may observe, That the account given by the new system of that furniture of the human understanding which is the gift of nature, and not the acquisition of our own reasoning faculty, is extremely lame and imperfect.
The natural furniture of the human understanding is of two kinds: First, The notions or simple apprehensions which we have of things: and, Secondly, The judgments or the belief which we have concerning them. As to our notions, the new system reduces them to two classes; ideas of sensation and ideas of reflection: the first are conceived to be copies of our sensations retained in the memory or ima- gination; the second to be copies of the operations of our minds, whereof we are conscious, in like manner retained in the memory or imagination: and we are taught, that these two comprehend all the materials about which the human understanding is or can be employed. As to our judg- ment of things, or the belief which we have concerning them, the new system allows no part of it to be the gift of nature, but holds it to be the acquisition of reason, and to be got by comparing our ideas, and perceiving their agree- 258 OF THE HUMAN MIND.
ments or disagreements. Now, I take this account, both of our notions and of our judgments or belief, to be ex- tremely imperfect; and I shall briefly point out some of its capital defects.
The division of our notions into ideas of sensation and ideas of reflection is contrary to all rules of logic; be- cause the second member of the division includes the first. For can we form clear and just notions of our sensations any other way than by reflection? Surely we cannot. — Sensation is an operation of the mind of which we are conscious; and we get the notion of sensation by reflect- ing upon that which we are conscious of. In like manner, doubting and believing are operations of the mind whereof we are conscious? and we get the notion of them by re- flecting upon what we are conscious of. The ideas of sensa- tion, therefore, are ideas of reflection, as much as the ideas of doubting or believing, or any other ideas whatsoever.
But to pass over the inaccuracy of this division, it is extremely incomplete. For since sensation is an opera- tion of the mind, as well as all the other things of which we form our notions by reflection; when it is asserted, that all our notions are either ideas of sensation or ideas of reflection, the plain English of this is, That mankind neither do, nor can think of any thing but of the operations of their own minds. Nothing can be more contrary to truth, or more contrary to the experience of mankind. I know that Locke, while he maintained this doctrine, be- lieved the notions which we have of body and of its qua- lities, and the notions which we have of motion and of space, to be ideas of sensation. But why did he believe this? Because he believed those notions to be nothing else but images of our sensations. If therefore the notions of body and its qualities, of motion and space, be not images of our sensations, will it not follow that those notions are not ideas of sensation? Most certainly.
There is no doctrine in the new system which more di- rectly leads to scepticism than this. And the author of the Treatise of Human Nature knew very well how to use it for that purpose: for if you maintain that there is any such existence as body or spirit, time or place, cause CHAP. VII.] CONCLUSION. 259 or effect, he immediately catches you between the horn3 of this dilemma; your notions of these existences are either ideas of sensation or ideas of reflection; if of sen- sation, from what sensation are they copied? if of reflec- tion, from what operations of the mind are they copied?
It is indeed to be wished, that those who have written much about sensation, and about the other operations of the mind, had likewise thought and reflected much, and with great care, upon those operations: but is it not very strange, that they will not allow it to be possible for man- kind to think of any thing else?