_Hyl._ Well, since it must be so, I am content to yield this point, and

acknowledge that heat and cold are only sensations existing in our minds.

But there still remain qualities enough to secure the reality of external

things.

_Phil._ But what will you say, Hylas, if it shall appear that the case is

the same with regard to all other sensible qualities(793), and that they

can no more be supposed to exist without the mind, than heat and cold?

_Hyl._ Then indeed you will have done something to the purpose; but that

is what I despair of seeing proved.

_Phil._ Let us examine them in order. What think you of _tastes_—do they

exist without the mind, or no?

_Hyl._ Can any man in his senses doubt whether sugar is sweet, or wormwood

bitter?

_Phil._ Inform me, Hylas. Is a sweet taste a particular kind of pleasure

or pleasant sensation, or is it not?

_Hyl._ It is.

_Phil._ And is not bitterness some kind of uneasiness or pain?

_Hyl._ I grant it.

_Phil._ If therefore sugar and wormwood are unthinking corporeal

substances existing without the mind, how can sweetness and bitterness,

that is, pleasure and pain, agree to them?

_Hyl._ Hold, Philonous, I now see what it was deluded me all this time.

You asked whether heat and cold, sweetness and bitterness, were not

particular sorts of pleasure and pain; to which I answered simply, that

they were. Whereas I should have thus distinguished:—those qualities, as

perceived by us, are pleasures or pains; but not as existing in the

external objects. We must not therefore conclude absolutely, that there is

no heat in the fire, or sweetness in the sugar, but only that heat or

sweetness, as perceived by us, are not in the fire or sugar. What say you

to this?

_Phil._ I say it is nothing to the purpose. Our discourse proceeded

altogether concerning sensible things, which you defined to be, _the

things we immediately perceive by our senses_. Whatever other qualities,

therefore, you speak of, as distinct from these, I know nothing of them,

neither do they at all belong to the point in dispute. You may, indeed,

pretend to have discovered certain qualities which you do not perceive,

and assert those insensible qualities exist in fire and sugar. But what

use can be made of this to your present purpose, I am at a loss to

conceive. Tell me then once more, do you acknowledge that heat and cold,

sweetness and bitterness (meaning those qualities which are perceived by

the senses), do not exist without the mind?

_Hyl._ I see it is to no purpose to hold out, so I give up the cause as to

those mentioned qualities. Though I profess it sounds oddly, to say that

sugar is not sweet.

_Phil._ But, for your farther satisfaction, take this along with you: that

which at other times seems sweet, shall, to a distempered palate, appear

bitter. And, nothing can be plainer than that divers persons perceive

different tastes in the same food; since that which one man delights in,

another abhors. And how could this be, if the taste was something really

inherent in the food?

_Hyl._ I acknowledge I know not how.

_Phil._ In the next place, _odours_ are to be considered. And, with regard

to these, I would fain know whether what hath been said of tastes doth not

exactly agree to them? Are they not so many pleasing or displeasing

sensations?

_Hyl._ They are.

_Phil._ Can you then conceive it possible that they should exist in an

unperceiving thing?

_Hyl._ I cannot.

_Phil._ Or, can you imagine that filth and ordure affect those brute

animals that feed on them out of choice, with the same smells which we

perceive in them?

_Hyl._ By no means.

_Phil._ May we not therefore conclude of smells, as of the other

forementioned qualities, that they cannot exist in any but a perceiving

substance or mind?

_Hyl._ I think so.

_Phil._ Then as to _sounds_, what must we think of them: are they

accidents really inherent in external bodies, or not?

_Hyl._ That they inhere not in the sonorous bodies is plain from hence:

because a bell struck in the exhausted receiver of an air-pump sends forth

no sound. The air, therefore, must be thought the subject of sound.

_Phil._ What reason is there for that, Hylas?

_Hyl._ Because, when any motion is raised in the air, we perceive a sound

greater or lesser, according to the air’s motion; but without some motion

in the air, we never hear any sound at all.

_Phil._ And granting that we never hear a sound but when some motion is

produced in the air, yet I do not see how you can infer from thence, that

the sound itself is in the air.

_Hyl._ It is this very motion in the external air that produces in the

mind the sensation of _sound_. For, striking on the drum of the ear, it

causeth a vibration, which by the auditory nerves being communicated to

the brain, the soul is thereupon affected with the sensation called

_sound_.

_Phil._ What! is sound then a sensation?

_Hyl._ I tell you, as perceived by us, it is a particular sensation in the

mind.

_Phil._ And can any sensation exist without the mind?

_Hyl._ No, certainly.

_Phil._ How then can sound, being a sensation, exist in the air, if by the

_air_ you mean a senseless substance existing without the mind?

_Hyl._ You must distinguish, Philonous, between sound as it is perceived

by us, and as it is in itself; or (which is the same thing) between the

sound we immediately perceive, and that which exists without us. The

former, indeed, is a particular kind of sensation, but the latter is

merely a vibrative or undulatory motion in the air.

_Phil._ I thought I had already obviated that distinction, by the answer I

gave when you were applying it in a like case before. But, to say no more

of that, are you sure then that sound is really nothing but motion?

_Hyl._ I am.

_Phil._ Whatever therefore agrees to real sound, may with truth be

attributed to motion?

_Hyl._ It may.

_Phil._ It is then good sense to speak of _motion_ as of a thing that is

_loud, sweet, acute, or grave_.

_Hyl._ I see you are resolved not to understand me. Is it not evident

those accidents or modes belong only to sensible sound, or _sound_ in the

common acceptation of the word, but not to _sound_ in the real and

philosophic sense; which, as I just now told you, is nothing but a certain

motion of the air?

_Phil._ It seems then there are two sorts of sound—the one vulgar, or that

which is heard, the other philosophical and real?

_Hyl._ Even so.

_Phil._ And the latter consists in motion?

_Hyl._ I told you so before.

_Phil._ Tell me, Hylas, to which of the senses, think you, the idea of

motion belongs? to the hearing?

_Hyl._ No, certainly; but to the sight and touch.

_Phil._ It should follow then, that, according to you, real sounds may

possibly be _seen_ or _felt_, but never _heard_.

_Hyl._ Look you, Philonous, you may, if you please, make a jest of my

opinion, but that will not alter the truth of things. I own, indeed, the

inferences you draw me into sound something oddly; but common language,

you know, is framed by, and for the use of the vulgar: we must not

therefore wonder if expressions adapted to exact philosophic notions seem

uncouth and out of the way.

_Phil._ Is it come to that? I assure you, I imagine myself to have gained

no small point, since you make so light of departing from common phrases

and opinions; it being a main part of our inquiry, to examine whose

notions are widest of the common road, and most repugnant to the general

sense of the world. But, can you think it no more than a philosophical

paradox, to say that _real sounds are never heard_, and that the idea of

them is obtained by some other sense? And is there nothing in this

contrary to nature and the truth of things?

_Hyl._ To deal ingenuously, I do not like it. And, after the concessions

already made, I had as well grant that sounds too have no real being

without the mind.

_Phil._ And I hope you will make no difficulty to acknowledge the same of

_colours_.

_Hyl._ Pardon me: the case of colours is very different. Can anything be

plainer than that we see them on the objects?

_Phil._ The objects you speak of are, I suppose, corporeal Substances

existing without the mind?

_Hyl._ They are.

_Phil._ And have true and real colours inhering in them?

_Hyl._ Each visible object hath that colour which we see in it.

_Phil._ How! is there anything visible but what we perceive by sight?

_Hyl._ There is not.

_Phil._ And, do we perceive anything by sense which we do not perceive

immediately?

_Hyl._ How often must I be obliged to repeat the same thing? I tell you,

we do not.

_Phil._ Have patience, good Hylas; and tell me once more, whether there is

anything immediately perceived by the senses, except sensible qualities. I

know you asserted there was not; but I would now be informed, whether you

still persist in the same opinion.

_Hyl._ I do.

_Phil._ Pray, is your corporeal substance either a sensible quality, or

made up of sensible qualities?

_Hyl._ What a question that is! who ever thought it was?

_Phil._ My reason for asking was, because in saying, _each visible object

hath that colour which we see in it_, you make visible objects to be

corporeal substances; which implies either that corporeal substances are

sensible qualities, or else that there is something beside sensible

qualities perceived by sight: but, as this point was formerly agreed

between us, and is still maintained by you, it is a clear consequence,

that your _corporeal substance_ is nothing distinct from _sensible

qualities_(794).

_Hyl._ You may draw as many absurd consequences as you please, and

endeavour to perplex the plainest things; but you shall never persuade me

out of my senses. I clearly understand my own meaning.

_Phil._ I wish you would make me understand it too. But, since you are

unwilling to have your notion of corporeal substance examined, I shall

urge that point no farther. Only be pleased to let me know, whether the

same colours which we see exist in external bodies, or some other.

_Hyl._ The very same.

_Phil._ What! are then the beautiful red and purple we see on yonder

clouds really in them? Or do you imagine they have in themselves any other

form than that of a dark mist or vapour?

_Hyl._ I must own, Philonous, those colours are not really in the clouds

as they seem to be at this distance. They are only apparent colours.

_Phil._ _Apparent_ call you them? how shall we distinguish these apparent

colours from real?

_Hyl._ Very easily. Those are to be thought apparent which, appearing only

at a distance, vanish upon a nearer approach.

_Phil._ And those, I suppose, are to be thought real which are discovered

by the most near and exact survey.

_Hyl._ Right.

_Phil._ Is the nearest and exactest survey made by the help of a

microscope, or by the naked eye?

_Hyl._ By a microscope, doubtless.

_Phil._ But a microscope often discovers colours in an object different

from those perceived by the unassisted sight. And, in case we had

microscopes magnifying to any assigned degree, it is certain that no

object whatsoever, viewed through them, would appear in the same colour

which it exhibits to the naked eye.

_Hyl._ And what will you conclude from all this? You cannot argue that

there are really and naturally no colours on objects: because by

artificial managements they may be altered, or made to vanish.

_Phil._ I think it may evidently be concluded from your own concessions,

that all the colours we see with our naked eyes are only apparent as those

on the clouds, since they vanish upon a more close and accurate inspection

which is afforded us by a microscope. Then, as to what you say by way of

prevention: I ask you whether the real and natural state of an object is

better discovered by a very sharp and piercing sight, or by one which is

less sharp?

_Hyl._ By the former without doubt.

_Phil._ Is it not plain from _Dioptrics_ that microscopes make the sight

more penetrating, and represent objects as they would appear to the eye in

case it were naturally endowed with a most exquisite sharpness?

_Hyl._ It is.

_Phil._ Consequently the microscopical representation is to be thought

that which best sets forth the real nature of the thing, or what it is in

itself. The colours, therefore, by it perceived are more genuine and real

than those perceived otherwise.

_Hyl._ I confess there is something in what you say.

_Phil._ Besides, it is not only possible but manifest, that there actually

are animals whose eyes are by nature framed to perceive those things which

by reason of their minuteness escape our sight. What think you of those

inconceivably small animals perceived by glasses? Must we suppose they are

all stark blind? Or, in case they see, can it be imagined their sight hath

not the same use in preserving their bodies from injuries, which appears

in that of all other animals? And if it hath, is it not evident they must

see particles less than their own bodies; which will present them with a

far different view in each object from that which strikes our senses(795)?

Even our own eyes do not always represent objects to us after the same

manner. In the jaundice every one knows that all things seem yellow. Is it

not therefore highly probable those animals in whose eyes we discern a

very different texture from that of ours, and whose bodies abound with

different humours, do not see the same colours in every object that we do?

From all which, should it not seem to follow that all colours are equally

apparent, and that none of those which we perceive are really inherent in

any outward object?

_Hyl._ It should.

_Phil._ The point will be past all doubt, if you consider that, in case

colours were real properties or affections inherent in external bodies,

they could admit of no alteration without some change wrought in the very

bodies themselves: but, is it not evident from what hath been said that,

upon the use of microscopes, upon a change happening in the humours of the

eye, or a variation of distance, without any manner of real alteration in

the thing itself, the colours of any object are either changed, or totally

disappear? Nay, all other circumstances remaining the same, change but the

situation of some objects, and they shall present different colours to the

eye. The same thing happens upon viewing an object in various degrees of

light. And what is more known than that the same bodies appear differently

coloured by candle-light from what they do in the open day? Add to these

the experiment of a prism which, separating the heterogeneous rays of

light, alters the colour of any object, and will cause the whitest to

appear of a deep blue or red to the naked eye. And now tell me whether you

are still of opinion that every body hath its true real colour inhering in

it; and, if you think it hath, I would fain know farther from you, what

certain distance and position of the object, what peculiar texture and

formation of the eye, what degree or kind of light is necessary for

ascertaining that true colour, and distinguishing it from apparent ones.

_Hyl._ I own myself entirely satisfied, that they are all equally

apparent, and that there is no such thing as colour really inhering in

external bodies, but that it is altogether in the light. And what confirms

me in this opinion is, that in proportion to the light colours are still

more or less vivid; and if there be no light, then are there no colours

perceived. Besides, allowing there are colours on external objects, yet,

how is it possible for us to perceive them? For no external body affects

the mind, unless it acts first on our organs of sense. But the only action

of bodies is motion; and motion cannot be communicated otherwise than by

impulse. A distant object therefore cannot act on the eye; nor

consequently make itself or its properties perceivable to the soul. Whence

it plainly follows that it is immediately some contiguous substance,

which, operating on the eye, occasions a perception of colours: and such

is light.

_Phil._ How! is light then a substance?

_Hyl._ I tell you, Philonous, external light is nothing but a thin fluid

substance, whose minute particles being agitated with a brisk motion, and

in various manners reflected from the different surfaces of outward

objects to the eyes, communicate different motions to the optic nerves;

which, being propagated to the brain, cause therein various impressions;

and these are attended with the sensations of red, blue, yellow, &c.

_Phil._ It seems then the light doth no more than shake the optic nerves.

_Hyl._ Nothing else.

_Phil._ And consequent to each particular motion of the nerves, the mind

is affected with a sensation, which is some particular colour.

_Hyl._ Right.

_Phil._ And these sensations have no existence without the mind.

_Hyl._ They have not.

_Phil._ How then do you affirm that colours are in the light; since by

_light_ you understand a corporeal substance external to the mind?

_Hyl._ Light and colours, as immediately perceived by us, I grant cannot

exist without the mind. But in themselves they are only the motions and

configurations of certain insensible particles of matter.

_Phil._ Colours then, in the vulgar sense, or taken for the immediate

objects of sight, cannot agree to any but a perceiving substance.

_Hyl._ That is what I say.

_Phil._ Well then, since you give up the point as to those sensible

qualities which are alone thought colours by all mankind beside, you may

hold what you please with regard to those invisible ones of the

philosophers. It is not my business to dispute about _them_; only I would

advise you to bethink yourself, whether, considering the inquiry we are

upon, it be prudent for you to affirm—_the red and blue which we see are

not real colours, but certain unknown motions and figures which no man

ever did or can see are truly so_. Are not these shocking notions, and are

not they subject to as many ridiculous inferences, as those you were

obliged to renounce before in the case of sounds?

_Hyl._ I frankly own, Philonous, that it is in vain to stand out any

longer. Colours, sounds, tastes, in a word all those termed _secondary

qualities_, have certainly no existence without the mind. But by this

acknowledgment I must not be supposed to derogate anything from the

reality of Matter, or external objects; seeing it is no more than several

philosophers maintain(796), who nevertheless are the farthest imaginable

from denying Matter. For the clearer understanding of this, you must know

sensible qualities are by philosophers divided into _Primary_ and

_Secondary_(797). The former are Extension, Figure, Solidity, Gravity,

Motion, and Rest; and these they hold exist really in Bodies. The latter

are those above enumerated; or, briefly, _all sensible qualities beside

the Primary_; which they assert are only so many sensations or ideas

existing nowhere but in the mind. But all this, I doubt not, you are

apprised of. For my part, I have been a long time sensible there was such

an opinion current among philosophers, but was never thoroughly convinced

of its truth until now.

_Phil._ You are still then of opinion that _extension_ and _figures_ are

inherent in external unthinking substances?

_Hyl._ I am.

_Phil._ But what if the same arguments which are brought against Secondary

Qualities will hold good against these also?

_Hyl._ Why then I shall be obliged to think, they too exist only in the

mind.

_Phil._ Is it your opinion the very figure and extension which you

perceive by sense exist in the outward object or material substance?

_Hyl._ It is.

_Phil._ Have all other animals as good grounds to think the same of the

figure and extension which they see and feel?

_Hyl._ Without doubt, if they have any thought at all.

_Phil._ Answer me, Hylas. Think you the senses were bestowed upon all

animals for their preservation and well-being in life? or were they given

to men alone for this end?

_Hyl._ I make no question but they have the same use in all other animals.

_Phil._ If so, is it not necessary they should be enabled by them to

perceive their own limbs, and those bodies which are capable of harming

them?

_Hyl._ Certainly.

_Phil._ A mite therefore must be supposed to see his own foot, and things

equal or even less than it, as bodies of some considerable dimension;

though at the same time they appear to you scarce discernible, or at best

as so many visible points(798)?

_Hyl._ I cannot deny it.

_Phil._ And to creatures less than the mite they will seem yet larger?

_Hyl._ They will.

_Phil._ Insomuch that what you can hardly discern will to another

extremely minute animal appear as some huge mountain?

_Hyl._ All this I grant.

_Phil._ Can one and the same thing be at the same time in itself of

different dimensions?

_Hyl._ That were absurd to imagine.

_Phil._ But, from what you have laid down it follows that both the

extension by you perceived, and that perceived by the mite itself, as

likewise all those perceived by lesser animals, are each of them the true

extension of the mite’s foot; that is to say, by your own principles you

are led into an absurdity.

_Hyl._ There seems to be some difficulty in the point.

_Phil._ Again, have you not acknowledged that no real inherent property of

any object can be changed without some change in the thing itself?

_Hyl._ I have.

_Phil._ But, as we approach to or recede from an object, the visible

extension varies, being at one distance ten or a hundred times greater

than at another. Doth it not therefore follow from hence likewise that it

is not really inherent in the object?

_Hyl._ I own I am at a loss what to think.

_Phil._ Your judgment will soon be determined, if you will venture to

think as freely concerning this quality as you have done concerning the

rest. Was it not admitted as a good argument, that neither heat nor cold

was in the water, because it seemed warm to one hand and cold to the

other?

_Hyl._ It was.

_Phil._ Is it not the very same reasoning to conclude, there is no

extension or figure in an object, because to one eye it shall seem little,

smooth, and round, when at the same time it appears to the other, great,

uneven, and angular?

_Hyl._ The very same. But does this latter fact ever happen?

_Phil._ You may at any time make the experiment, by looking with one eye

bare, and with the other through a microscope.

_Hyl._ I know not how to maintain it; and yet I am loath to give up

_extension_, I see so many odd consequences following upon such a

concession.

_Phil._ Odd, say you? After the concessions already made, I hope you will

stick at nothing for its oddness. [(799) But, on the other hand, should it

not seem very odd, if the general reasoning which includes all other

sensible qualities did not also include extension? If it be allowed that

no idea, nor anything like an idea, can exist in an unperceiving

substance, then surely it follows that no figure, or mode of extension,

which we can either perceive, or imagine, or have any idea of, can be

really inherent in Matter; not to mention the peculiar difficulty there

must be in conceiving a material substance, prior to and distinct from

extension, to be the _substratum_ of extension. Be the sensible quality

what it will—figure, or sound, or colour, it seems alike impossible it

should subsist in that which doth not perceive it.]

_Hyl._ I give up the point for the present, reserving still a right to

retract my opinion, in case I shall hereafter discover any false step in

my progress to it.

_Phil._ That is a right you cannot be denied. Figures and extension being

despatched, we proceed next to _motion_. Can a real motion in any external

body be at the same time both very swift and very slow?

_Hyl._ It cannot.

_Phil._ Is not the motion of a body swift in a reciprocal proportion to

the time it takes up in describing any given space? Thus a body that

describes a mile in an hour moves three times faster than it would in case

it described only a mile in three hours.

_Hyl._ I agree with you.

_Phil._ And is not time measured by the succession of ideas in our minds?

_Hyl._ It is.

_Phil._ And is it not possible ideas should succeed one another twice as

fast in your mind as they do in mine, or in that of some spirit of another

kind?

_Hyl._ I own it.

The Works of George Berkeley. Vol. 1 of 4: Philosophical Works, 1705-21 · 第 34 / 51 段