is presupposed just as much as in calling it a sensible quality;
only that with Locke ‘quality’ conveyed the notion of inherence in
the substance, power that of relation to an effect not _in_ the
substance itself. ‘Secondary qualities are nothing but the powers
which _substances_ have to produce several ideas in us by our senses,
which ideas are not in the things themselves, otherwise than as
anything is in its cause.’ (Book II. chap, xxiii. sec. 9.) ‘Most of
the simple ideas, that make up our complex ideas of substances, are
only powers ... or relations to other substances (or, as he explains
elsewhere, ‘relations to our perceptions,’ [1]), and are not really
in the substance considered barely in itself.’ (Book II. chap,
xxiii. sec. 37, and xxxi. 8.) That this implies the inclusion of the
idea of cause in that of substance, appears from Locke’s statement
that ‘whatever is considered by us to operate to the producing any
particular simple idea which did not before exist, hath thereby in
our minds the relation of a cause.’ (Book II. chap. xxvi. sec. 1.)
Thus to be conscious of the reality of a simple idea, as that which
is not made by the subject of the idea, but results from a power
in a thing, is to have the idea of substance as cause. This latter
idea must be the condition of the consciousness of reality. If the
consciousness of reality is implied in the beginning of knowledge, so
must the correlative ideas be of cause and substance.
[1] Book II. chap. xxi. sec. 3.
How do we know that ideas correspond to reality of things? Locke’s
answer.
54. On examining Locke’s second rehearsal of his theory in the fourth
book of the Essay--that ‘On Knowledge’--we are led to this result
quite as inevitably as in the book ‘On Ideas.’ He has a special
chapter on the ‘reality of human knowledge,’ where he puts the
problem thus:--‘It is evident the mind knows not things immediately,
but only by the intervention of the ideas it has of them. Our
knowledge therefore is real only so far as there is a conformity
between our ideas and the reality of things. But what shall be here
the criterion? How shall the mind, when it perceives nothing but its
own ideas, know that they agree with things themselves?’ (Book IV.
chap. iv. sec. 3.) It knows this, he proceeds to show, in the case
of simple ideas, because ‘since the mind can by no means make them
to itself, they must be the product of things operating on the mind
in a natural way. ... Simple ideas are not fictions of our fancies,
but the natural and regular productions of things without us, really
operating upon us; and so carry with them all the conformity which
is intended, or which our state requires, for they represent to us
things under those appearances which they are fitted to produce in
us; whereby we are enabled to distinguish the sorts of particular
substances,’ &c. &c. (Book IV. chap. iv. sec. 4.) The whole force
of this passage depends on the notion that simple ideas are already
to the subject of them not his own making, but the product of a
thing, which in its relation to these ideas is a ‘particular sort of
substance.’ It is the reception of such ideas, so related, that Locke
calls ‘sensitive knowledge of particular existence,’ or a ‘perception
of the mind, employed about the particular existence of finite
beings without us.’ (Book IV. chap. ii. sec. 14.) This, however, he
distinguishes from two other ‘degrees of knowledge or certainty,’
‘intuition’ and ‘demonstration,’ of which the former is attained when
the agreement or disagreement of two ideas is perceived immediately,
the latter when it is perceived mediately through the intervention
of certain other agreements or disagreements (less or more), each of
which must in turn be perceived immediately. Demonstration, being
thus really but a series of intuitions, carries the same certainty
as intuition, only it is a certainty which it requires more or less
pains and attention to apprehend. (Book IV. chap. ii. sec. 4.) Of
the ‘other perception of the mind, employed about the particular
existence of finite beings without us,’ which ‘passes under the
name of knowledge,’ he explains that although ‘going beyond bare
probability, it reaches not perfectly to either of the foregoing
degrees of certainty.’ ‘There can be nothing more certain,’ he
proceeds, ‘than that the idea we receive from an external object
is in our minds; this is intuitive knowledge. But whether there be
anything more than barely that idea in our minds, whether we can
thence certainly infer the existence of anything without us which
corresponds to that idea, is that whereof some men think there may be
a question made; because men may have such ideas in their minds, when
no such thing exists, no such object affects their senses.’ (Book IV.
chap. ii. sec. 14.)
It assumes that simple ideas are consciously referred to things that
cause them.
55. It is clear that here in his very statement of the question
Locke begs the answer. If the intuitive certainty is that ‘the idea
we _receive from an external object_ is in our minds,’ [1] how is
it possible to doubt whether such an object exists and affects
our senses? This impossibility of speaking of the simple idea,
except as received from an object, may account for Locke’s apparent
inconsistency in finding the assurance of the reality of knowledge
(under the phrase ‘evidence of the senses’) just in that ‘perception’
which reaches not to intuitive or demonstrative certainty, and only
‘passes under the name of knowledge.’ In the passage just quoted he
shows that he is cognizant of the distinction between the simple
idea and the perception of an existence corresponding to it, and in
consequence distinguishes this perception from proper intuition, but
in the very statement of the distinction it eludes him. The simple
idea, as he speaks of it, becomes itself, as consciously ‘received
from an external object,’ the perception of existence; just as we
have previously seen it become the judgment of identity or perception
of the ‘agreement of an idea with itself,’ which is his first kind of
knowledge.
[1] I do not now raise the question, What are here the ideas, which
must be immediately perceived to agree or disagree in order to make
it a case of ‘intuitive certainty’ or knowledge according to Locke’s
definition. See below, paragraphs 59, 101, and 147.
Lively ideas real, because they must be effects of things.
56. In short, with Locke the simple idea, the perception of existence
corresponding to the idea, and the judgment of identity, are
absolutely merged, and in mutual involution, sometimes under one
designation, sometimes under another, are alike presented as the
beginning of knowledge. As occasion requires, each does duty for the
other. Thus, if the ‘reality of knowledge’ be in question, the simple
idea, which is given, is treated as involving the perception of
existence, and the reality is established. If in turn this perception
is distinguished from the simple idea, and it is asked whether the
correspondence between idea and existence is properly matter of
knowledge, the simple idea has only to be treated as involving the
judgment of identity, which again involves that of existence, and
the question is answered. So in the context under consideration
(Book IV. chap. ii. sec. 14), after raising the question as to the
existence of a thing corresponding to the idea, he answers it by
the counter question, ‘whether anyone is not invincibly conscious
to himself of a different perception, when he looks on the sun by
day, and thinks on it by night; when he actually tastes wormwood, or
smells a rose, or only thinks on that savour or odour? We as plainly
find the difference there is between any idea revived in our minds
by our own memory, and actually coming into our minds by our senses,
as we do between any two distinct ideas.’ The force of the above
lies in its appeal to the perception of identity, or--to apply the
language in which Locke describes this perception--the knowledge that
the idea which a man calls the smell of a rose is the very idea it
is. [1] The mere difference in liveliness between the present and
the recalled idea, which, as Berkeley and Hume rightly maintained,
is the only difference between them as mere ideas, cannot by itself
constitute the difference between the knowledge of the presence of a
thing answering to the idea and the knowledge of its absence. It can
only do this if the more lively idea is _identified_ with past lively
ideas as a representation of one and the same thing which ‘agrees
with itself’ in contrast to the multiplicity of the sensations,
its signs. Only in virtue of this identification can either the
liveliness of the idea show that the thing--the sun or the rose--is
there, or the want of liveliness that it is not, for without it there
would be no thing to be there or not to be there. It is because
this identification is what Locke understands by the first sort of
perception of agreement between ideas, and because he virtually finds
this perception again in the simple idea, that the simple idea is
to him the index of reality. But if so, the idea in its primitive
simplicity is the sign of a thing that is ever the same in the same
relations, and we find the ‘workmanship of the mind,’ its inventions
of substance, cause, and relation, in the very rudiments of knowledge.
[1] See above, paragraph 25.
Present sensation gives knowledge of existence.
57. With that curious tendency to reduplication, which is one of his
characteristics, Locke, after devoting a chapter to the ‘reality of
human knowledge,’ of which the salient passage as to simple ideas has
been already quoted, has another upon our ‘knowledge of existence.’
Here again it is the sensitive knowledge of things actually present
to our senses, which with him is merely a synonym for the simple
idea, that is the prime criterion. (Book IV. chap. iii. secs. 5 and
2, and chap. ii. sec. 2.) After speaking of the knowledge of our own
being and of the existence of a God (about which more will be said
below), he proceeds, ‘No particular man can know the existence of any
other being, but only when, by actually 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. It is therefore the actual receiving of
ideas from without, that gives us notice of the existence of other
things, and makes us know that something doth exist at that time
without us, which causes that idea in us, though perhaps we neither
know nor consider how it does it; for it takes not from the certainty
of our senses and the ideas we receive by them, that we know not the
manner wherein they are produced; _e.g._ whilst I write this, I have,
by the paper affecting my eyes, that idea produced in my mind, which,
whatever object causes, I call _white_; by which I know that the
quality or accident (_i.e._ whose appearance before my eyes always
causes that idea) doth really exist, and hath a being without me. And
of this the greatest assurance. I can possibly have, and to which
my faculties can attain, is the testimony of my eyes, which are the
proper and sole judges of this thing, whose testimony I have reason
to rely on, as so certain, that I can no more doubt whilst I write
this, that I see white and black, and that something really exists
that causes that sensation in me, than that I write and move my
hand.’ (Book IV. chap. xi. secs. 1, 2.)
Reasons why its testimony must be trusted.
58. Reasons are afterwards given for the assurance that the
‘perceptions’ in question are produced in us by ‘exterior causes
affecting our senses.’ The first _(a)_ is, that ‘those that want
the organs of any sense never can have the ideas belonging to that
sense produced in their mind.’ The next _(b)_, that whereas ‘if
I turn my eyes at noon toward the sun, I cannot avoid the ideas
which the light or the sun then produces in me;’ on the other hand,
‘when my eyes are shut or windows fast, as I can at pleasure recall
to my mind the ideas of light or the sun, which former sensations
had lodged in my memory, so I can at pleasure lay them by.’ Again
_(c)_, ‘many of those ideas are produced in us with pain which
afterwards we remember without the least offence. Thus the pain of
heat or cold, when the idea of it is revived in our minds, gives
us no disturbance; which, when felt, was very troublesome, and is
again, when actually repeated; which is occasioned by the disorder
the external object causes in our body, when applied to it.’ Finally
(d), ‘our senses in many cases bear witness to the truth of each
other’s report, concerning the existence of sensible things without
us. He that sees a fire may, if he doubt whether it be anything
more than a bare fancy, feel it too.’ Then comes the conclusion,
dangerously qualified: ‘When our senses do actually convey into our
understandings 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 our apprehensive
faculties, and actually produce that idea which we then perceive;
and we cannot so far distrust their testimony as to doubt that such
collections of simple ideas, as we have observed by our senses to
be united together, actually exist together. But this knowledge
extends as far as the present testimony of our senses, employed about
particular objects, that do then affect them, and no farther. For
if I saw such a collection of simple ideas as is wont to be called
man, existing together one minute since, and am now alone; I cannot
be certain that the same man exists now, since there is no necessary
connexion of his existence a minute since with his existence now. By
a thousand ways he may cease to be, since I had the testimony of my
senses for his existence.’ (Book IV. chap. xi. sec. 9.)
How does this account fit Locke’s definition of knowledge?
59. Upon the ‘knowledge of the existence of things,’ thus
established, it has to be remarked in the first place that, after
all, according to Locke’s explicit statement, it is not properly
knowledge. It is ‘an assurance that deserves the name of knowledge’
(Book IV. chap. ii. sec. 14, and xi. sec. 3), yet being neither
itself an intuition of agreement between ideas, nor resoluble into a
series of such intuitions, the definition of knowledge excludes it.
Only if existence were itself an ‘idea,’ would the consciousness of
the agreement of the idea with it be a case of knowledge; but to make
existence an idea is to make the whole question about the agreement
of ideas, as such, with existence, as such, unmeaning. To seek escape
from this dilemma by calling the consciousness of the agreement
in question an ‘assurance’ instead of knowledge is a mere verbal
subterfuge. There can be no assurance of agreement between an idea
and that which is no object of consciousness at all. If, however,
existence is an object of consciousness, it can, according to Locke,
be nothing but an idea, and the question as to the _assurance_
of agreement is no less unmeaning than the question as to the
_knowledge_ of it. The raising of the question in fact, as Locke puts
it, implies the impossibility of answering it. It cannot be raised
with any significance, unless existence is external to and other than
an idea. It cannot be answered unless existence is, or is given in,
an object of consciousness, _i.e._ an idea.
Locke’s account of the testimony of sense renders his question as to
its veracity superfluous.
60. As usual, Locke disguises this difficulty from himself, because
in answering the question he alters it. The question, _as he asks
it_, is whether, given the idea, we can have posterior assurance of
something else corresponding to it. The question, _as he answers
it_, is whether the idea includes the consciousness of a real thing
as a constituent; and the answer consists in the simple assertion,
variously repeated, that it does. It is clear, however, that this
answer to the latter question does not answer, but renders unmeaning,
the question as it is originally asked. If, according to Locke’s own
showing, there is nowhere for anything to be found by us but in our
‘ideas’ or our consciousness--if the _thing_ is given in and with the
idea, so that the idea is merely the thing _ex parte nostrâ_--then to
ask if the idea agrees with the thing is as futile as to ask whether
hearing agrees with sound, or the voice with the words it utters.
That the thing is so given is implied throughout Locke’s statement
of the ‘assurance we have of the existence of material beings,’ as
well as of the confirmations of this assurance. If the ‘idea which
I call white’ means the knowledge that ‘the property or accident
(_i.e._ whose appearance before my eyes always causes that idea)
doth really exist and hath a being without me,’ then consciousness
of existence--outward, permanent, substantive, and causative
existence--is involved in the idea, and no ulterior question of
agreement between idea and existence can properly arise. But unless
the simple idea is so interpreted, the senses have no testimony to
give. If it is so interpreted, no extraneous ‘reason to rely upon
the testimony’ can be discovered, for such reason can only be a
repetition of the testimony itself.
Confirmations of the testimony turn upon the distinction between
‘impression’ and ‘idea’.
61. This becomes clearer upon a view of the confirmations of the
testimony, as Locke gives them. They all, we may remark by the way,
presuppose a distinction between the simple idea as originally
represented and the same as recalled or revived. This distinction,
fixed by the verbal one between ‘impression’ and ‘idea,’ we shall
find constantly maintained and all-important in Hume’s system; but in
Locke, though upon it (as we shall see) rests his distinction between
real and nominal essence and his confinement of general knowledge
to the latter, it seems only to turn up as an afterthought. In the
account of the reality and adequacy of ideas it does not appear at
all. There the distinction is merely between the simple idea, as
such, and the complex, as such, without any further discrimination of
the simple idea as originally produced from the same as recalled. So,
too, in the opening account of the reception of simple ideas (Book
II. chap. xii. sec. 1), ‘Perception,’ ‘Retention,’ and ‘Discerning’
are all reckoned together as alike forms of the _passivity_ of the
mind, in contrast with its activity in combination and abstraction,
though retention and discerning have been previously described
in terms which imply activity. In the ‘confirmations’ before us,
however, the distinction between the originally produced and the
revived is essential.
They depend on language which presupposes the ascription of sensation
to an outward cause.
62. The first turns upon the impossibility of producing an idea _de
novo_ without the action of sensitive organs; the two next upon
the difference between the idea as produced through these organs
and the like idea as revived at the will of the individual. It is
hence inferred that the idea as originally produced is the work of
a thing, which must exist _in rerum naturâ_, and by way of a fourth
‘confirmation’ the man who doubts this in the case of one sensation
is invited to try it in another. If, on seeing a fire, he thinks it
‘bare fancy,’ _i.e._ doubts whether his idea is caused by a thing,
let him put his hand into it. This last ‘confirmation’ need not be
further noticed here, since the operation of a producing thing is
as certain or as doubtful for one sensation as for another. [1] Two
certainties are not more sure than one, nor can two doubts make a
certainty. The other ‘confirmations’ alike lie in the words ‘product’
and ‘organ.’ A man has a certain ‘idea:’ afterwards he has another
like it, but differing in liveliness and in the accompanying pleasure
or pain. If he already has, or if the ideas severally bring with
them, the idea of a producing outward thing to which parts of his
body are organs, on the one hand, and of a self ‘having power’ on the
other, then the liveliness, and the accompanying pleasure or pain,
may become indications of the action of the thing, as their absence
may be so of the action of the man’s self; but not otherwise. Locke
throughout, in speaking of the simple ideas as produced or recalled,
implies that they carry with them the consciousness of a cause,
either an outward thing or the self, and only by so doing can he find
in them the needful ‘confirmations’ of the ‘testimony of the senses.’
This testimony is confirmed just because it distinguishes of itself
between the work of ‘nature,’ which is real, and the work of the
man, which is a fiction. In other words, the confirmation is nothing
else than the testimony itself--a testimony which, as we have seen,
since it supposes consciousness, as such, to be consciousness _of a
thing_, eliminates by anticipation the question as to the agreement
of consciousness with things, as with the extraneous.
[1] To feel the object, in the sense of touching it, had a special
significance for Locke, since touch with him was the primary
‘revelation’ of body, as the solid. More will be said of this when we
come to consider his doctrine of ‘real essence,’ as constituted by
primary qualities of body. See below, paragraph 101.
This ascription means the clothing of sensation with invented
relations.
63. The distinction between the real and the fantastic, according
to the passages under consideration, thus depends upon that between
the work of nature and the work of man. It is the confusion between
the two works that renders the fantastic possible, while it is the
consciousness of the distinction that sets us upon correcting it.
Where all is the work of man and professes to be no more, as in the
case of ‘mixed modes,’ there is no room for the fantastic (Book II.
chap. xxx. sec. 4, and Book IV. chap. iv. sec. 7); and where there
is ever so much of the fantastic, it would not be so for us, unless
we were conscious of a ‘work of nature,’ to which to oppose it. But
on looking a little closer we find that to be conscious of an idea
as the work of nature, in opposition to the work of man, is to be
conscious of it under relations which, according to Locke, are the
inventions of man. It is nothing else than to be conscious of it as
the result of ‘something having power to produce it’ (Book II. chap.
xxxi. sec. 2), _i.e._ of a substance, to which it is related as a
quality. ‘Nature’ is just the ‘something we know not what,’ which
is substance according to the ‘_abstract_ idea’ thereof. Producing
ideas, it exercises powers, as it essentially belongs to substance
to do, according to our _complex_ idea of it. (Book II. chap, xxiii.
secs. 9, 10.) But substance, according to Locke, whether as abstract
or complex idea, is the ‘workmanship of the mind,’ and power, as a
relation (Book II. chap. xxi. sec. 3, and chap. xxv. sec. 8), ‘is
not contained in the real existence of things.’ Again, the idea of
substance, as a source of power, is the same as the idea of cause.
‘Whatever is considered by us to operate to the producing any
particular simple idea, which did not before exist, hath thereby in
our minds the relation of a cause.’ (Book II. chap. xxvi. sec. 1.)
But the idea of cause is not one ‘that the mind has of things as they
are in themselves,’ but one that it gets by its own act in ‘bringing
things to, and setting them by, one another.’ (Book II. chap. xxv.
sec. 1.) Thus it is with the very ideas, which are the workmanship
of man, that the simple idea has to be clothed upon, in order to
‘testify’ to its being real, _i.e._ (in Locke’s sense) not the work
of man.
What is meant by restricting the testimony of sense to _present_
existence?