1. FROM An Essay Concerning Human Understanding[1]
~BY John Locke
1. The way shown how we come by any knowledge, sufficient to prove it not
innate. It is an established opinion among some men, that there are in the
understanding certain innate principles; some primary notions, characters, as
it were, stamped upon the mind of man which the soul receives in its very first
being, and brings into the world with it. It would be sufficient to convince
unprejudiced readers of the falseness of this supposition, if I should only
show (as I hope I shall in the following parts of this discourse) how men,
barely by the use of their natural faculties, may attain to all the knowledge
they have, without the help of any innate impressions, and may arrive at
certainty, without any such original notions or principles . .. .
2. General Assent the great Argument. There is nothing more commonly
taken for granted, than that there are certain principles, both speculative and
practical (for they speak of both), universally agreed upon by all mankind,
which therefore, they argue, must needs be constant impressions which the souls
of men receive in their first beings, and which they bring into the world with
them, as necessarily and really as they do any of their inherent faculties.
3. Universal Consent proves nothing innate. This argument, drawn from
universal consent, has this misfortune in it, that if it were true in matter of
fact that there were certain truths wherein all mankind agreed, it would not
prove them innate, if there can be any other way shown how men may come to that
universal agreement in the things they do consent in, which I presume may be
done.
4. "What is, is," and "it is impossible for the same Thing
to be and not to be," not universally assented to. But, which is
worse, this argument of universal consent, which is made use of to prove innate
principles, seems to me a demonstration that there are none such; because there
are none to which all mankind give an universal assent. I shall begin with the
speculative, and instance in those magnified principles of demonstration,
"Whatsoever is, is" and "It is impossible for the same thing to
be, and not to be"; which, of all others, I think, have the most allowed
title to innate. These have so settled a reputation of maxims universally
received that it will no doubt be thought strange if anyone should seem to
question it. But yet I take liberty to say that these propositions are so far
from having an universal assent that there are a great part of mankind to whom
they are not so much as known.
5. Not on the Mind naturally imprinted, because not known to Children,
Idiots, &.-For, first, it is evident that all children and idiots have
not the least apprehension or thought of them; and the want of that is enough
to destroy that universal assent which must needs be the necessary concomitant
of all innate truths: it seeming to me near a contradiction to say that there
are truths imprinted on the soul which it perceives or understands not;
imprinting, if it signify anything, being nothing else but the making certain
truths to be perceived. For to imprint anything on the mind without the mind's
perceiving it, seems to me hardly intelligible. If therefore children and
idiots have souls, have minds, with those impressions upon them, they must
unavoidably perceive them, and necessarily know and assent to these truths;
which since they do not, it is evident that there are no such impressions. For
if they are not notions naturally imprinted, how can they be innate, and if
they are notions imprinted, how can they be unknown? To say a notion is
imprinted on the mind, and yet at the same time to say that the mind is
ignorant of it, and never yet took notice of it, is to make this impression nothing.
No proposition can be said to be in the mind which it never yet knew, which it
was never yet conscious of.
…Let us suppose the mind to
be, as we say, a blank tablet (tabula rasa) of white paper, void of all
characters, without any ideas; how comes it to be furnished? Whence comes it by
that vast store, which the busy and boundless fancy of man has painted on it
with almost endless variety? Whence has it all the materials of reason and knowledge?
To this I answer in one word, from experience: in that all our knowledge is
founded, and from that it ultimately derives itself.
2. FROM New Essays on Human Understanding[2]
BY Gottfried Wilhelm von Leibniz
The question at issue is
whether the soul in itself is entirely empty, like the tablet upon which
nothing has yet been written (tabula rasa), as is the view of Aristotle and the
author of the Essay (Locke), and whether all that is traced on it comes solely
from the senses and from experience; or whether the soul contains originally
the principles of various notions and doctrines which external objects merely
awaken from time to time, as I believe, with Plato and even with the Schoolmen,
and with all those who take in this sense the passage of St. Paul (Romans,
2:15) where he remarks that the law of God is written in the heart .... From
this there arises another question, whether all truths depend on experience,
that is to say, on induction and examples, or whether there are some that have
some other basis. For if some events can be foreseen before any trial has been
made of them, it is clear that we must here contribute something of our own.
The senses, although necessary for all our actual knowledge, are not sufficient
to give us the whole of it, since the senses never give anything except
examples, that is to say, particular or individual truths. All examples which
confirm a general truth, however numerous they may be, are not enough to
establish the universal necessity of this same truth; for it does not follow
that what has happened will happen again in the same way.
It would seem 'that necessary
truths, such as are found in pure mathematics, and especially in arithmetic and
in geometry, must have principles the proof of which does not depend on examples,
nor, consequently, on the testimony of the senses, although without the senses
it would never have occurred to us to think of them. This ought to be well recognised; Euclid has so well understood it that he often
demonstrates by reason what is obvious enough through experience and by
sensible images. Logic also, together with metaphysics and ethics, one of which
forms natural theology and the other natural jurisprudence, are full of such
truths; and consequently their proof can only come from internal principles,
which are called innate. It is true that we must not imagine that these eternal
laws of the reason can be read in the soul as in an open book, as the edict of
the praetor can be read in his album without difficulty or research; but it is
enough that they can be discovered in us by dint of attention, for which
opportunities are given by the senses. The success of experiments serves also
as confirmation of the reason, very much as proofs serve in arithmetic for
better avoiding error of reckoning when the reasoning is long.
It seems that our able author
claims that there is nothing potential in us and nothing even of which we are
not at any time actually conscious; but he cannot mean this strictly, or his
opinion would be too paradoxical; for acquired habits and the contents of our
memory are not always consciously perceived and do not even always come to our
aid at need, although we often easily bring them back to mind on some slight
occasion which makes us remember them, just as we need only the beginning of a
song to remember the song. Also he modifies his assertion in other places by
saying that there is nothing in us of which we have not been at least formerly
conscious. But besides the fact that no one can be sure by reason alone how far
our past apperceptions, which we may have forgotten, may have gone, especially
in view of the Platonic doctrine of reminiscence, which, mythical as it is, is
not, in part at least, incompatible with bare reason; in addition to this, I
say, why is it necessary that everything should be acquired by us through the
perceptions of external things, and that nothing can be unearthed in ourselves?
Is our soul, then, such a blank that, besides the images borrowed from without,
it is nothing? . .. [T]here are a thousand indications that lead us to think
that there are at every moment numberless perceptions in us, but without
apperception and without reflections; that is to say, changes in the soul
itself of which we are not conscious, because the impressions are either too
slight and too numerous, or too even, so that they have nothing sufficient to
distinguish them one from the other; but, joined to others, they do not fail to
produce their effect and to make themselves felt at least confusedly in the
mass.
FROM
An Essay Concerning Human Understanding[3]
BY John Locke
1. Concerning the simple
ideas of Sensation, it is to be considered-that whatsoever is so constituted in
nature as to be able, by affecting our senses, to cause any perception in the
mind, doth thereby produce in the understanding a simple idea; which, whatever
be the external cause of it, when it comes to be taken notice of by our
discerning faculty, it is by the mind looked on and considered there to be a
real positive idea in the understanding, as much as any other whatsoever;
though, perhaps, the cause of it be but a privation of the subject.
2. Thus the ideas of heat and
cold, light and darkness, white and black, motion and rest, are equally clear
and positive ideas in the mind; though perhaps, some of the causes which
produce them are barely privations, in those subjects from whence our senses
derive those ideas. These the understanding, in its view of them, considers all
as distinct positive ideas, without taking notice ofthe
causes that produce them: which is an inquiry not belonging to the idea, as it
is in the understanding, but to the nature of the things existing without us.
These are two very different things, and carefully to be distinguished; it
being one thing to perceive and know the idea of white or black, and quite
another to examine what kind of particles they must be, and how ranged in the
superficies, to make any object appear white or black.
7. To discover the nature of
our ideas the better, and to discourse of them intelligibly, it will be
convenient to distinguish them as they are ideas or perceptions in our minds;
and as they are modifications oj matter in the bodies
that cause such perceptions in us: that so we may not think (as perhaps usually
is done) that they are exactly the images and resemblances of something
inherent in the subject; most of those of sensation being in the mind no more
the likeness of something existing without us, than the names that stand for
them are the likeness of our ideas, which yet upon hearing they are apt to
excite in us.
8. Whatsoever the mind
perceives in itself, or is the immediate object of perception, thought, or
understanding, that I call idea; and the power to produce any idea in our mind,
I call quality of the subject wherein that power is. Thus a snowball having the
power to produce in us the ideas of white, cold, and round-the power.
PRIMARY QUALITIES:
Qualities thus considered in
bodies are, First, such as are utterly inseparable from the body, in what state
soever it be; and such as in all the alterations and
changes it suffers, all the force can be used upon it, it constantly keeps; and
such as sense constantly fInds in every particle of
matter which has bulk enough to be perceived; and the mind fInds
inseparable from every particle of matter, though less than to make itself
singly be perceived by our senses: e.g. Take a grain of wheat, divide it into
two parts; each part has still solidity, extension, figure, and mobility: divide
it again, and it retains still the same qualities; and so divide it on, till
the parts become insensible; they must retain still each of them alt those
qualities. For division (which is all that a mill, or pestle, or any other
body, does upon another, in reducing it to insensible parts) can never take
away either solidity, extension, figure, or mobility from any
body, but only makes two or more distinct separate masses of matter, of
that which was but one before; all which distinct masses, reckoned as so many
distinct bodies; after division, make a certain number. These I call original or primary qualities of body, which I think we may observe to produce
simple ideas in us, viz. solidity, extension, figure, motion or rest, and
number.
SECONDARY QUALITIES:
Secondly, such qualities
which in truth are nothing in the objects themselves but powers to produce
various sensations in us by their primary qualities, i.e., by the bulk, figure,
texture, and motion of their insensible parts, as colours,
sounds, tastes, &c. These I call secondary qualities. To these might be
added a third sort, which are allowed to be barely powers; though they are as
much real qualities in the subject as those which I, to comply with the common
way of speaking, call qualities, but for distinction, secondary qualities. For
the power in fire to produce a new colour, or
consistency, in wax or clay--by its primary qualities, is as much a quality in
fire, as the power it has to produce in me a new idea or sensation of warmth or
burning, which I felt not before-by the same primary qualities, viz. the bulk,
texture, and motion of its insensible parts.
Primary
qualities:
If then external objects be not united to our
minds when they produce ideas therein; and yet we perceive these original qualities
in such of them as singly fall under our senses, it is evident that some motion
must be thence continued by our nerves, or animal spirits, by some parts of our
bodies, to the brains or the seat of sensation, there to produce in our minds
the particular ideas we have of them. And since the extension, figure, number, and
motion of bodies of an observable bigness, may be perceived at a distance by
the sight, it is evident some singly imperceptible bodies must come from them
to the eyes, and thereby convey to the brain some motion; which produces these
ideas which we have of them in us.
Secondary qualities:
After the same manner that
the ideas of these original qualities are produced in us, we may conceive that
the ideas of secondary qualities are also produced, viz. by the operation of
insensible particles on our senses. For, it being manifest that there are
bodies and good store of bodies, each whereof are so small, that we cannot by
any of our senses discover either their bulk, figure, or motion-as is evident
in those particles of the air and water, and others extremely smaller than
those; perhaps as much smaller than the particles of air and water, as the
particles of air and water are smaller than peas or hail-stones;-let us suppose
at present that the different motions and figures, bulk and number, of such
particles, affecting the several organs of our senses, produce in us those
different sensations which we have from the colours
and smells of bodies; e.g. that a violet, by the impulse of such insensible
particles of matter, of peculiar figures and bulks, and in different degrees
and modifications of their motions, causes the ideas of the blue colour, and sweet scent of that flower to be produced in
our minds. It being no more impossible to conceive that God should annex such
ideas to such motions, with which they have no similitude, than that he should
annex the idea of pain to the motion of a piece of steel dividing our flesh,
with which that idea hath no resemblance.
What I have said concerning colours and smells may be understood also of tastes and
sounds, and other the like sensible qualities; which, whatever reality we by
mistake attribute to them, are in truth nothing in the objects themselves, but
powers to produce various sensations in us; and depend on those primary
qualities, viz. bulk, figure, texture, and motion of parts [as I have said).
Therefore,
I think it easy to draw this
observation-that the ideas of primary qualities of bodies are resemblances of
them, and their patterns do really exist in the bodies themselves, but the ideas
produced in us by these secondary qualities have no resemblance of them at all.
There is nothing like our ideas, existing in the bodies themselves. They are,
in the bodies we denominate from them, only a power to produce those sensations
in us: and what is sweet, blue, or warm in idea, is but the certain bulk, fIgure, and motion of the insensible parts, in the bodies
themselves, which we call so.
Flame is denominated hot and
light; snow, white and cold; and manna, white and sweet, from the ideas they produce
in us. Which qualities are corrunonly thought to be
the same in those bodies that those ideas are in us, the one the perfect
resemblance of the other, as they are in a mirror, and it would by most men be
judged very extravagant if one should say otherwise. And yet he that will
consider that the same fire that, at one distance produces in us the sensation
of warmth, does, at a nearer approach, produce in us the far different
sensation of pain, ought to bethink himself what reason he has to say-that this
idea of warmth, which was produced in him by fire, is actually in the fire; and
his idea of pain, which the same fIre produced in him
the same way, is not in the fire. Why
are whiteness and coldness in snow, and pain not, when it produces the one and
the other idea in The particular bulk, number, figure, and motion of the parts
of fire or snow are really in them-whether anyone's senses perceive them or no:
and therefore they may be called reaL qualities,
because they really exist in those bodies. But light, heat,
whiteness, or coldness, are
no more really in them than sickness or pain is in manna. Take away the
sensation of them; let not the eyes see light or colours,
nor the ears hear sounds; let the palate not taste, nor the nose smell, and all
colours, tastes, odours,
and sounds, as they are such particular ideas, vanish and cease, and are
reduced to their causes, i.e., bulk, figure, and motion of parts.
The knowledge of the
existence of any other thing we can have only by sensation: for there being no
necessary connexion of real existence with any idea a
man hath in his memory; nor of any other existence but that of God with the
existence of any particular man: no particular man can know the existence of
any other being, but only when, by actual operating upon him, it makes itself
perceived by him. For, the having the idea of anything in our mind, no more
proves the existence of that thing, than the picture of a man evidences his
being in the world, or the visions of a dream make thereby a true history.
Locke’s
alternative to the strict Cartesian limitation of knowledge:
Locke
then answers Descartes:
8. But yet, if after all this
anyone will be so sceptical as to distrust. his
senses, and to affirm all that we see and hear, feel and taste, think and do,
during our whole being, is but the series and deluding appearance of a long
dream, whereof there is no reality; and therefore will question the existence
of all things, or our knowledge of anything: I must desire him to consider,
that, if all be a dream, then he doth but dream that he makes the question, and
so it is not much matter that a waking man should answer him. But yet, if he
pleases, he may dream that I make him this answer, that the certainty of things
existing in rerum natura when
we have the testimony of our senses for it is not only as great as our frame
can attain to, but as our condition needs. For, our faculties being suited not
to the full extent of being, nor to a perfect, clear, comprehensive knowledge
of things free from all doubt and scruple; but to the preservation of us, in
whom they are; and accommodated to the use of life: they serve to our purpose
well enough, if they will but give us certain notice of those things, which are
convenient or inconvenient to us. For he that sees a candle burning, and hath
experimented the force of its flame by putting his finger in it, will little
doubt that this is something existing without him, which does him harm, and
puts him to great pain: which is assurance enough, when no man requires greater
certainty to govern his actions by than what is as certain as his actions
themselves. And if our dreamer pleases to try whether the glowing heat of glass
furnace be barely a wandering imagination in a drowsy man's fancy, by putting his
hand into it, he may perhaps be wakened into a certainty greater than he could
wish, that it is something more than bare imagination. So that this evidence is
as great as we can desire, being as certain to us as our pleasure or pain,
i.e., happiness or misery; beyond which we have no concernment, either of
knowing or being. Such an assurance of the existence of things without us is
sufficient to direct us in the attaining the good and avoiding the evil which
is caused by them, which is the important concernment we have of being made
acquainted with them.
9. In summary, then, when our
senses do actually convey into our understanding
any idea, we cannot but be
satisfied that there doth something at
that time really exist
without us, which doth affect
our senses, and by them give notice of itself to apprehensive
faculties, and actually
produce that idea which we then perceive.
Return
to the traditional metaphysical notion of substance:
Hence, when we talk or think
of any particular sort of corporeal substances, as horse, stone, &c.,
though the idea we have of either of them be but the complication or collection
of those several simple ideas of sensible qualities which we used to find
united in the thing called "horse" or "stone"; yet because
we cannot conceive how they should subsist alone, nor one in another, we
suppose them existing in, and supported by some common subject; which support
we denote by the name "substance," though it be certain we have no
clear or distinct idea of that thing we suppose a support.
[1] John Locke, An Essay Concerning Human Understanding. ed. A. C. Fraser, Oxford: Clarendon Press, 1894.
[2] "Leibniz's Rebuttal," from New Essays on Human Understanding. by Gottfried Wilhelm von Leibniz, trans. A. G. Langley. Reprinted by permission of Open Court Publishing Company, a division of Carus Publishing Company, Peru, IL. Copyright © 1949 by Open Court Publishing.
[3] John Locke, An Essay Concerning Human Understanding, ed. A. C. Fraser, Oxford: Clarendon Press, 1894.