King: Life and Letters of John Locke, pp. 333-341


MEMORY. When we revive in our minds the idea of anything that we have before observed to exist, this we call memory; viz. to recollect in our minds the idea of our father or brother. But when, from the observations we have made of divers particulars, we make a general idea to represent any species in general, as man; or else join several ideas together, which we never observed to exist together, we call it imagination. So that memory is always the picture of something, the idea whereof has existed before in our thoughts, as near the life as we can draw it; but imagination is a picture drawn in our minds without reference to a pattern.

And here it may be observed that the ideas of memory, like painting after the life, come always short, i. e. want something of the original. For whether a man would remember the dreams he had in the night, or the sights of a foregoing day, some of the traces are always left out, some of the circumstances are forgotten; and those kind of pictures, like those represented successively by several looking-glasses, are the more dim and fainter the further they are off from the original object. For the mind, endeavouring to retain only the traces of the pattern, losing by degrees a great part of them, and not having the liberty to supply any new colours or touches of its own, the picture in the memory every day fades and grows dimmer, and oftentimes is quite lost.

But the imagination, not being tied to any pattern, but adding what colours, what ideas it pleases, to its own workmanship, making originals of its own which are usually very bright and clear in the mind, and sometimes to that degree that they make impressions as strong and as sensible as those ideas which come immediately by the senses from external objects,—so that the mind takes one for the other, and its own imagination for realities.

And in this, it seems, madness consists, and not in the want of reason; for allowing their imagination to be right, one may observe that madmen usually reason right from them: and I guess that those who are about madmen, will find that they make very little use of their memory, which is to recollect particulars past with their circumstances: but having any particular idea suggested to their memory, fancy dresses it up after its own fashion, without regard to the original.

Hence also one may see how it comes to pass that those that think long and intently upon one thing, come at last to have their minds disturbed about it, and to be a little cracked as to that particular. For by repeating often with vehemence of imagination the ideas that do belong to, or may be brought in about, the same thing, a great many whereof the fancy is wont to furnish, these at length come to take so deep and impression, that they all pass for clear truths and realities, though perhaps the greater part of them have at several times been supplied only by the fancy, and are nothing but the pure effects of the imagination.

This at least is the cause of several errors and mistakes amongst men, even when it does not wholly unhinge the brains, and put all government of the thoughts into the hands of the imagination; as it sometimes happens when the imagination, being much employed, and getting the mastery about any one thing, usurps the dominion over all the other faculties of the mind in all other. But how this comes about, or what it is that gives it on such an occasion that empire,—how it comes thus to be let loose, I confess, I cannot guess. If that were once known, it would be no small advance towards the easier curing of this malady; and perhaps to that purpose it may not be amiss to observe what diet, temper, or other circumstances they are, that set the imagination on fire, and make it active and imperious. This I think, that having often recourse to one's memory, and tying down the mind strictly to the recollecting things past precisely as they were, may be a means to check those extravagant or towering flights of the imagination. And it is good often to divert the mind from that which it has been earnestly employed about, or which is its ordinary business, to other objects, and to make it attend to the informations of the senses and the things they offer to it.      J. L. 1678.


Madness seems to be nothing but a disorder in the imagination, and not in the discursive faculty; for one shall find amongst the distract, those who fancy themselves kings, &c., who discourse and reason right enough upon the suppositions and wrong fancies they have taken. And any sober man may find it in himself in twenty occasions, viz.—in a town where he has not been long resident, let him come into a street that he is pretty well acquainted with at the contrary end to what he imagined, he will find all his reasonings about it so out of order and so inconsistent with the truth, that should he enter into debate upon the situation of the houses, the turnings on the right or left hand, &c. &c., with one who knew the place perfectly, and had the right ideas which way he was going, he would seem little better than frantic.

This, I believe, most people may have observed to have happened to themselves, especially when they have been carried up and down in coaches, and perhaps may have found it sometimes difficult to set their thoughts right, and reform the mistakes of their imagination. And I have known some who, upon the wrong impressions which were at first made upon their imaginations, could never tell which was north or south in Smithfield, though they were no very ill geographers: and when by the sun and the time of the day they were convinced of the position of that place, yet they could not tell how to reconcile it to other parts of the town that were adjoining to it, but out of sight; and were very apt to relapse again, as soon as either the sun disappeared, or they were out of sight of the place, into the mistakes and confusion of their old ideas. From whence one may see of what moment it is to take care that the first impressions we settle upon our minds be conformable to the truth and to the nature of thing; or else all our meditations and discourse thereupon will be nothing but perfect raving.


The foundation of error and mistake in most men lies in having obscure or confused notions of things, or by reason of their confused ideas, doubtful and obscure words; our words always in their signification depending upon our ideas, being clear or obscure proportionably as our notions are so, and sometimes have little more but the sound of the word for the notion of the thing. For in the discursive faculty of the mind, I do not find that men are so apt to err; but it avails little that their syllogisms are right, if their terms be insignificant and obscure, or confused and indetermined, or that in their internal discourse deductions be regular, if their notions be wrong. Therefore, in our discourse with others, the greatest care is to be had that we be not misled or imposed on by the measure of their words, where the fallacy oftener lies than in faulty consequences.

And in considering by ourselves to take care of our notions, where a man argues right upon wrong notions or terms, he does like a madman; were he makes wrong consequences, he does like a fool: madness seeming to me to lie more in the imagination, and folly in the discourse.


Space, in itself, seems to be nothing but a capacity, or possibility, for extended beings or bodies to be, or exist, which we are apt to conceive infinite; for there being in nothing no resistance, we have a conception very natural and very true, that let bodies be already as far extended as you will, yet, other new bodies should be created, they might exist where there are now no bodies: viz. a globe of a foot diameter might exist beyond the utmost superficies of all bodies now existing; and because we have by our acquaintance with bodies got the idea of the figure and distance of the superficial part of a globe of a foot diameter, we are apt to imagine the space where the globe exists to be really something, to have a real existence before and after its existence there. Whereas, in truth, it is really nothing, and so has no opposition nor resistance to the being of such a body there; though we, applying the idea of a natural globe, are apt to conceive it as something so far extended, and these are properly the imaginary spaces which are so much disputed of. But as for distance, I suppose that to be the relation of two bodies or beings near or remote to one another, measurable by the ideas we have of distance taken from solid bodies; for were there no beings at all, we might truly say there were no distances. The fallacy we put upon ourselves which inclines us to think otherwise is this, that whenever we talk of distance, we first suppose some real beings existing separate from one another, and then, without taking notice of that supposition, and the relation that results from their placing one in reference to another, we are apt to consider that space as some positive real being existing without them: whereas, as it seems to me, to be but a bare relation; and when we suppose them to be, viz. a yard asunder, it is no more but to say extended in a direct line to the proportion of three feet or thirty-six inches distance, whereof by use we have got the idea: this gives us the notion of distance, and the vacuum that is between them is understood by this, that bodies of a yard long that come between them, thrust or remove away nothing that was there before.

1. I take it for granted that I can conceive a space without a body; for, suppose the universe as big as you will, I can, without the bounds of it, imagine it possible to thrust out or create any the most solid body of any figure, without removing from the place it possesses anything that was there before. Neither does it imply any contradiction to suppose a space so empty within the bounds of the universe, that a body may be brought into it without removing from thence any other' and if this be not granted, I cannot see how one can make out any motion supposing your bodies of what figures or bulk you please, as I imagine it is easy to demonstrate.

If it be possible to suppose nothing, or, in our thoughts, to remove all manner of beings from any place, then this imaginary space is just nothing, and signifies no more but a bare possibility that body may exist where now there is none. If it be impossible to suppose pure nothing, or to extend our thoughts where there is, or we can suppose, no being, this space void of body must be something belonging to the being of the Deity. But be it one or the other, the idea we have of it we take from the extension of bodies which fall under our senses; and this idea of extension being settled in our minds, we are able, by repeating that in our thoughts, without annexing body or impenetrability to it, to imagine spaces where there are no bodies—which imaginary spaces, if we suppose all other beings absent, are purely nothing, but merely a possibility that body might there exist. Or if it be a necessity to suppose a being there, it must be God, whose being we thus make, i. e. suppose extended, but not impenetrable: but be it one or the other, extension seems to be mentally separable from body, and distance nothing but the relation of space, resulting from the existence of two positive beings; or, which is all one, two parts of the same being.


Besides the considering things barely and separately in themselves, the mind considers them also with respect, i. e. at the same time looking upon some other, and this we call relation. So that if the mind so considers anything that another is necessarily supposed, this is relation; there is that which necessarily makes us consider two things at once, or makes the mind look on two things at once, and hence it is that relative terms or words that signify this relation so denominate one thing, as that they always intimate or denote another; viz. father, countryman, bigger, distant; so that whatsoever necessarily occasions two things, looked on as distinct, this connection in our thoughts of whatsoever it be founded in, that is properly relation, which perhaps may serve to give a little light to that great obscurity which has caused so much dispute about the nature of space, whether it be something or nothing, created or eternal. For when we speak of space (as ordinarily we do) as the abstract distance, it seems to me to be a pure relation, and we call it distance; but when we consider it as the distance or space between the extremities of a continued body, whose continued parts do, or are supposed to, fill all the interjacent space, we call it extension, and it is looked on to be a positive inherent property of the body, because it keeps constantly with it, always the same, and every particle has its share of it; whereas, whether you consider the body in whole mass, or in the least particles of the body, it appears to me to be nothing but the relation of the distance of the extremities. But when we speak of space in general, abstract and separate from all consideration of any body at all or any other being; it seems not then to be any real thing, but the consideration of a bare possibility of body to exist: to this, I foresee, there will lie two great objections:—

1st. The Cartesians will except against me as speaking of space without body, which they make to be the same thing; to whom let me say, that if spacium be corpus, and corpus spacium, then it is as true too that extensio is corpus, and corpus extensio, which is a pretty harsh kind of expression and that which is so distant from truth, that I do not remember that I have anywhere met with it from them; and yet I would fain know any other difference between extensio and spacium than that which I have above mentioned. If they will say omne extensum et omnis res positiva extensa corpus, et vice versâ, I fully consent. But then it is only to say that body is the only being capable of distance between its own parts, which is extension (for I do not know why angels may not be capable of the relation of distance, in respect of one another), which shows plainly the difference of the words extension, which is for distance, a part of the same body, or that which is considered but as one body, and that of space, which is the distance between any two beings, without the consideration of body interjacent.

Besides this, there seems to me this great and essential difference between space and body, that body is divisible into separable parts, but space is not. This, I think, is so plain that it needs no proof; for if one take a piece of matter, of an inch square, for example, and divide it into two, the parts will be separated if set at further distance one from another; but yet nobody, I think, amongst those who are most for the reality of space, say the parts of space are or can be removed to a further distance one from another. And he that, imagining the idea of a space of an inch square, can tell how to separate the parts of it, and remove them one from another, has, I confess, a much more powerful fancy than I.

It is no more strange, therefore, that extension, which is the relation of distance between parts of the same being, should be proper only to body, which alone has parts, than that the relation of filiation should be proper only to men.

To my supposition, that space, as it may be conceived antecedent to and void of all bodies, or, if you will, all determinate beings, is nothing but the idea of the possibility of the existence of body; for, when one says there is space for another world as big as this, it seems to me to be no more than there is no repugnancy why another world as big as this might not exist; and in this sense space may be said to be infinite; and so in effect space, as antecedent to body, or some determinate being, is in effect nothing—To this I say will be objected, that space being, as it is, capable of greater and less, cannot properly be nothing.

To this I say, that space, antecedent to all determinate beings, is not capable of greater or less. The mistake lies in this, that we, having been accustomed to the measures of a foot, an ell, a mile, &c. &c., can easily frame ideas of them, where we suppose no body to be even beyond the bounds of the world, but our having ideas in our head proves not the existence of anything without us. But you will say, is not the space of a foot beyond the extremity of the universe less than the space of a yard? I answer, yes; that the idea of one, which I place there, is bigger than the idea of the other; but that there is anything real there existing, I deny; or by saying or imagining the space of a foot or yard beyond the extremity of the world, would suppose or mean anything more than that a body of a foot or a yard (of which I have the idea) may exist there, I deny. Indeed, should a body be placed a foot distant from the utmost extremity of the universe, one might say it was a foot distant from the world, which seems to me to be a bare relation, resulting from its position there, without supposing that space to be any real being existing there before, and interposed between them, but only that a real body of such dimensions may be placed between them without removing them further one from the other. For the relation makes itself appear in this, that whatsoever is so spoke of requires its correlative; and therefore, speaking of the universe, one cannot say it is distant, because without it we suppose no other determinate or finite being which may be the other term of this relation.

It will be answered, perhaps, that one may suppose a point in that empty space, and then say it is a foot from that point. I answer, one may as easily suppose a body as a point, if the point be quid reale; if not, it being nothing, one cannot say the extremity or superficies of the world is a foot from nothing; so that be it a point, or body, or what other being one pleases, that is supposed there, it is evidence there is always required some real existence to be the other term of the relation.

And after all the suppositions that can be made, it can never truly be said that the utmost superficies of the world is a foot distant from anything, if there be nothing really existing beyond it, but only that imaginary space.

That which makes us so apt to mistake in this point, I think, is this, that having been all our lifetime accustomed to speak ourselves, and hear all others speak of space, in phrases that import it to be a real thing, as to occupy or take up so much space, we come to be possessed with this prejudice, that it is a real thing, and not a bare relation. And that which helps to it is, that by constant conversing with real sensible things, which have this relation of distance one to another, which we, by the reason just now mentioned, mistake for a real positive thing, we are apt to think that it as really exists beyond the utmost extent of all bodies, or finite beings, though there be no such beings there to sustain it, as it does here amongst bodies, which is not true. For though it be true that the black lines drawn on a rule have the relation one to another of an inch distance, they being real sensible things; and though it be also true that I, knowing the idea of an inch, can imagine that length without imagining body, as well as I can imagine a figure without imagining body; yet it is no more true that there is any real distance in that which we call imaginary space, than that there is any real figure there.

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