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19 Locke, Essay Epistle and I.i.1-4,6-8;
II.i.1-8,20,23-25; ii, viii.1-6, iii-vi; vii.1-2,7-10 Sensation
–
Locke, Essay I.iv.25 Though John Locke’s Essay concerning human understanding appeared three years after However, another, much more significant
factor behind the positive reception of Locke’s work was its agreement with
the increasingly republican and anti-authoritarian political views of the
day. Unlike Descartes, Locke was not
primarily motivated to write his book on human understanding in order to
provide a justification for a certain kind of philosophy of nature. Instead, he was motivated by social,
religious, and political concerns. The
introductory Epistle to the Essay
contains a famous allusion to these concerns.
Were
it fit to trouble thee with the History of this Essay, I should tell thee,
that five or six Friends, meeting at my Chamber, and discoursing on a Subject
very remote from this, found themselves quickly at a stand, by the
Difficulties that rose on every side.
After we had a while puzzled our selves, without coming any nearer a
Resolution of those Doubts which perplexed us, it came into my Thoughts, that
we took a wrong course; and that, before we set our selves upon Enquiries of
that Nature, it was necessary to examine our own Abilities, and see, what
Objects our Understandings were, or were not fitted to deal with. [Epistle, Nidditch 7, Winkler 1-2] James Tyrell, one of the “friends”
present at this famous meeting, later reported that the subject of discussion
had not been any topic in natural philosophy, but rather the principles of
morality and revealed religion. It was
the foundations of our knowledge of these topics that Locke was most concerned
to investigate. And Locke made no
secret of the conclusions he hoped to draw from that investigation. Rather than establish a particular doctrine
beyond any hope of contestation, Locke hoped that, by clearly drawing the
bounds between what it is actually possible to know and what can only be
entertained as a matter of opinion he would, “prevail with the busy Mind of
Man, to be more cautious in meddling with things exceeding its Comprehension;
to stop, when it is at the utmost Extent of its Tether; and to sit down in a
quiet Ignorance of those Things, which, upon Examination, are found to be
beyond the reach of our Capacities,” avoiding “Disputes about Things, to
which our Understandings are not suited” in favour of a general toleration of
the contrary opinions of others (I.i.4). For Locke, doing this was not tantamount
to arguing for scepticism or discounting the efficacy of all of our knowing
powers. He considered that there are
things that we can know, many of them concerning the moral matters of most
concern to us. By drawing the boundaries
between what can be known and what cannot he hoped to avoid the sceptical
funk that people often fall into when, having carried their researches beyond
anything they can hope to achieve and gotten nowhere, they turn in disgust to
the contrary opinion that nothing at all can be known. But he also hoped to prevent people from
disputing about things that we cannot hope to know for sure to be true and
mount a powerful argument for toleration of the contrary opinions of others
in cases where knowledge is beyond our reach and the best we can manage is to
form opinions. The general project of examining what
things our understandings are and are not capable of coming to know is one
that Locke found to be hindered, rather than helped, by the philosophy of Descartes. Despite his avowedly great concern to
proceed from absolutely certain first principles, and not accept anything
that he could not clearly and distinctly perceive to be true, Descartes was
not very reflective about his own understanding or about the other operations
of his mind, such as imagining, willing, judging, and believing. As has been noted in past chapters,
Descartes never really paused to consider how he could tell a clear and
distinct perception on the part of the understanding apart from a natural
instinct, or either apart from a hasty judgment. He had more or less simply helped himself
to these notions, as if they were patently evident. As far as Locke was concerned, this was
tantamount to an open invitation to others to do the same, and base their
most fondly cherished beliefs not on reasoning or evidence, but the bald
affirmation that these beliefs are patently evident to the understanding,
innately known, or divinely inspired through a special gift of Grace,
illuminating the understanding with a power it could not resist.
The natural concomitant of “enthusiastic”
religious practices was a belief in the priesthood of all believers (or at
least, those among them — the “Saints” — who had been elected for salvation
and chosen by God to receive his Grace).
These practices and beliefs were inimical to all forms of authority,
be they ecclesiastical, civil, or military.
The Tudor and Stuart monarchs in Apprehensive of yet more violent
consequences were the enthusiastic “Country” and Episcopalian and Catholic
“Court” parties in England to continue to inflame one another’s passions,
friends of Locke’s such as Charles II’s one-time Prime Minister, Shaftesbury,
had gotten involved in plots to prevent James’s succession. When those plots had failed and been
discovered Locke himself, as an associate of the plotters, had been forced into
exile in As far as Locke was concerned, all of
these civil upheavals had arisen from people’s absolute conviction of the
correctness of their opposed beliefs on matters of morals and revealed
religion, a conviction that had fostered a spirit of intolerance and
disputation that was eventually carried to arms. And, to reiterate, as far as Locke was
concerned, the philosophy of Descartes, with its uncritical attitude towards
the difference between understanding, belief, faith, and opinion, had done
more to invite than to remedy this circumstance. Locke took the proper antidote to
intolerance and disputation to rest with a careful examination of the powers
of our understanding. Knowledge, as far as Locke was concerned, arises when
we make judgments about the significance and implications of the information
available to us. For Locke, as for Descartes,
this information was presumed to take the form of “ideas” that are
apprehended by the understanding. Judgments assert the existence of relations between ideas, and
are made true or false by whether the ideas actually prove upon inspection to
exhibit the relations affirmed in the judgment. The limits of our knowledge are accordingly
coincident with what ideas we can actually apprehend, and what content those
ideas exhibit. What was needed, therefore, was an
examination of the origin and nature of our ideas. If we could once agree on what ideas we
truly possess, precisely ascertain the content of those ideas, reject those
that are perhaps not even ideas at all, but merely unintelligible nonsense or
meaningless words masquerading as rational thought, determine what in general
can be inferred from these ideas, and determine what can and cannot be
accepted on the basis faith or revelation in the absence of a clearly
apprehended relation between ideas, then perhaps, Locke hoped, a way would be
cleared for us to end our disputations or at least develop a more tolerant
attitude to opposed beliefs. This, accordingly, was the project Locke
set himself at the outset of the essay.
As he put it, it was to “enquire into the Original, Certainty, and
Extent of humane Knowledge; together, with the Grounds and Degrees of Belief,
Opinion, and Assent” (Essay
I.i.2). But Locke immediately went on
to propose to undertake this enquiry in a startling way. “I shall not at present meddle with the
Physical Consideration of the Mind,” he wrote, “or trouble my self to
examine, wherein its Essence consists, or by what Motions of our Spirits, or
Alterations of our Bodies, we come to have any Sensations by our Organs, or
any Ideas in our Understandings; and whether those Ideas do in their
Foundation, any, or all of them, depend on Matter or no.” How, we might well wonder, could Locke
propose to examine the origin and nature of our ideas without considering how
sensory stimulation affects the brain or the extent to which ideas are the
products of alterations in the matter of the brain? For Hobbes this would have been
inconceivable and even Descartes, dualist though he was, was nonetheless
intensely concerned to determine how alterations in the body affect the mind
and what the ideas that are present in the mind tell us about our own body
and its material states. It bears noting that, unlike Hobbes and
Descartes, Locke had been trained as a physician and worked in that capacity
for a part of his life. He would have
attended anatomical lectures and have had a very clear sense of the dim
prospects the science of his day held out for making any progress in
uncovering how sensory stimulation affects the brain or how the brain works
within itself. Rather than attempt to gain knowledge of
the origin and nature of ideas by the method of observing what goes on in the
sense organs, nerves, and brain, Locke proposed a rather different method:
the “Historical, plain Method,” as he famously called it (I.i.2). The “Historical, plain Method” is the method
of first-person, introspective observation or reflective
self-consciousness. It begins with
meditations on one’s own ideas as they appear in consciousness and then seeks
to uncover the ways in which those ideas are worked up into knowledge claims
by means of introspectively evident processing operations — operations that
we may not always attend to, but that we can, with a bit of effort, reflect
upon and observe in action within ourselves.
As Locke put it, it involves considering “the discerning Faculties of
a Man, as they are employ’d about the Objects,
which they have to do with” (I.i.2).
It does not really matter, Locke claimed, what physical processes
first gave rise to our ideas. All that
matters is what ideas we have to start with and what we can proceed to do
with them once we have them. The “Historical, plain Method” was
coincidentally paralleled by the method employed by However, the “Historical, plain Method”
faces a challenge —
one that Locke acknowledged, but never addressed and that
consequently remains a persistent source of ambiguity and frustration
throughout the pages of the Essay. The method begins with introspective
identification of the information originally available for us to process into
knowledge claims: information that for Locke takes the form of a collection
of “ideas.” But it is very difficult
to say exactly what an idea is for Locke.
At I.i.8 he defined “idea” as “whatsoever is the Object of the
Understanding when a Man thinks” or “whatever it is which the Mind can be employ’d about in thinking.” But these are ambiguous phrases that might
be understood in at least three different ways. At least some of the objects we are
concerned with when thinking are naturally taken to be the objects that exist
outside of us in the surrounding world.
And, as odd as it may be to speak of the external object as if it were
an “idea” the mind is working with, Locke at least seems to have done so on
some occasions (II.viii.8). But when
he gave examples of ideas Locke included on his lists things like colours,
tastes, and smells — things which most of his early modern contemporaries had
since the time of Galileo considered to have no existence outside of the body
or the mind of the being that senses them.
And, as a matter of fact, Locke was fond of describing ideas in terms
that suggest that they are mental images or pictures of external things —
images or pictures that may not resemble their objects in all respects
(II.i.25, II,viii.3, II.xi.17, III.iii.7, IV.xi.1). However, on yet other occasions, Locke described
ideas in terms that suggest that they are not any sort of object, either
external or internal, but are rather actions or operations. Locke maintained that we have ideas of our
own mental operations, such as perceiving, remembering, willing, imagining,
and understanding. But the way we get
these ideas is simply by “taking notice” of those operations (II.i.4). The idea is not an image or picture of the
operation. Neither is it that very
image or operation. It seems rather to
consist in the further operation of “taking notice” of the fact that one is
perceiving, remembering, willing, etc.
Perceiving, remembering, willing, etc. are the objects we take notice
of, but the idea of these objects
seems to consist in the operation of taking notice of them. Did Locke mean to use the term “idea”
indifferently in all of these three senses, recognizing them each as a
distinct phenomenon that nonetheless deserves to be lumped in with the others
in a larger class? Or was his
considered view that one of the senses is primary and the others can be
reduced to it? The Essay does not say. Whatever difficulties there may be with
Locke’s project, its aim is one that merits a final comment. Locke was out to emancipate the individual
knower from the shackles of authority, just as many of his contemporaries
were out to emancipate the subject from the authority of the King. For Locke, republicanism was not just a
political doctrine, concerned with rights and powers within the state, but an
epistemological doctrine, concerned with the determination of truth. Locke’s own words put it best. And it was of no small advantage
to those who affected to be Masters and Teachers, to make this the Principle
of Principles, That Principles must
not be questioned: For having once established this Tenet, That there are
innate Principles, it put their Followers upon a necessity of receiving some
Doctrines as such; which was to take [their followers] off from their own
Reason and Judgment, and put them upon believing and taking [these purported
principles] upon trust, without farther examination: In which posture of
blind Credulity, they might be more easily governed by, and made useful to
some sort of Men, who had the skill and office to principle [i.e., instruct]
and guide them. Nor is it a small
power it gives one Man over another, to have the Authority to be the Dictator
of Principles, and Teacher of unquestioned Truths; and to make a Man swallow
that for an innate Principle, which may serve to his purpose, who teacheth them. [Essay
I.iv.24] In contrast, Locke maintained that it is
the natural cognitive capacities of individuals exercised upon the things
themselves that are the best judges of truth, and he took this “republican”
epistemology so far as to hold that even expert opinion ought not to be
allowed to determine the views of individuals — though only on matters of
“probability” and at the cost of requiring that all individuals tolerate one
another’s contrary opinions on such matters. It was views such as these that made
Locke’s Essay one of the most
popular readings among the founders of the American Revolution. QUESTIONS
ON THE
1. What was the
main question that the Essay concerning human understanding was
written to answer?
2. What has so far
served as the main impediment to the advancement of knowledge?
3. In what does the
“Historical, plain Method” consist?
4. What are the
main consequences of a failure to inquire into the limits of what can be
known by our understanding?
5. What does the
term, “idea,” stand for?
6. What are the two
sources of ideas?
7. What exactly is
conveyed to our minds by our senses?
8. What are the
“originals” from which our ideas “take their beginnings?”
9. What evidence
did Locke offer for supposing that all ideas originate from either sensation
or reflection? 10.
Do we only ever experience one simple idea at a
time? 11.
What makes simple ideas simple? 12.
Is it possible for us to spontaneously create ideas
on our own? 13.
Do we have ideas of privations? 14.
What did Locke consider to be the likely causes of
our ideas of white and black? 15.
Did Locke think it is even likely that any of our
ideas could be caused by privations? 16.
What is solidity and how does it differ from
hardness? 17.
Why does the mind consider solidity to be a feature
even of bodies that are too small to see? 18.
What does it mean for a body to fill a space? 19.
How does the extension of body differ from that of
space? NOTES
ON THE In Book II of the Essay Locke turned to his proper project: the anatomy of our
knowing powers. There are three parts
to this project. First, Locke tried to
determine what information is available to our knowing powers to work with,
or, as he preferred to put it, what sorts of ideas are given to the
mind. Then he tried to determine what
sorts of things we can and cannot come to know on the basis of this
information. Finally, he inquired into
what things we can accept on faith or trust, even though they may be beyond
our knowledge. The first of these tasks, the survey of the information available
to the understanding to work with, is undertaken over Book II of the Essay. Over the course of this book,
Locke identified the main sources from which we originally receive
information or ideas, and what sorts of ideas we receive from these
sources. He then identified various
operations that the mind is capable of performing on originally received
ideas and identified various derivative ideas that result from these
operations. Over Essay II.i-viii he took on just the
first of these tasks: identifying the main sources from which we originally
receive ideas and what sorts of ideas we receive from these sources. For Locke, there are three sources of
ideas: sensation, reflection, and imagination. However, imagination is not an original
source of ideas. It generates new
ideas only by repeating, compounding, dividing, comparing, abstracting, and
naming previously obtained ideas. So
there are just two ultimate sources of ideas, sensation and reflection. Sensation. Sensation is the most basic of these
remaining two ways, but also the most difficult to understand properly. In general, Locke thought that the ideas
that arise from sensation are those we get when we observe external objects
(II.i.2). But it is important to be
clear about just what this means. For
Locke, the observation of external objects is not something that we do; it is
rather something that is done to us.
We are passive when receiving ideas by sensation (II.i.25). For observation to take place, objects must
first affect our sense organs. The
effects that objects have on our sense organs are then conveyed to the brain,
which Locke described as the mind’s “presence room” (II.iii.1). (A presence room was a room where a person
went in order to have an audience with the Sovereign.) Once there, the effects somehow cause the
mind to have or become aware of an idea.
As Locke wrote at II.i.3: when I say the senses convey [ideas]
into the mind, I mean, they from external Objects convey into the mind what
produces there those Perceptions. The
claim remains frustratingly ambiguous.
Is “perceptions” used as a synonym for “ideas,” in which case the
claim would be that what is conveyed into the mind is something that causes
ideas to arise in the mind? Or are
ideas the things that are perceived, so that what is conveyed into the mind
is something that produces a perception of something else, called an
idea? And is anything literally
conveyed into the mind or is it
just the case that the occurrence of certain brain states is somehow
connected with the emergence of perceptions in the mind? At II.23 Locke defined sensation as
“such an Impression or Motion, made in some part of the Body, as produces
some Perception in the Understanding.”
This suggests that what is conveyed is not conveyed into the mind but only into the brain (the mind’s “presence
room”). Somehow, this conveyance has
an effect on the mind, giving rise to an idea (perception) or the perception
of an idea. According to II.23,
sensations are motions of body parts, not ideas. Ideas are things perceived by the
understanding. Importantly, and far from
trivially, Locke seems to have thought that the perceptions produced in the
understanding are not perceptions of the very things that cause those
perceptions — of the motions produced in our body parts. At Essay
II.viii.4 Locke wrote, at least speculatively, that “all Sensation” is
“produced in us, only by different degrees and modes of Motion in our animal
Spirits, variously agitated by external Objects,” so that “the abatement of
any former motion, must as necessarily produce a new sensation, as the
variation or increase of it; and so introduce a new Idea.” But the ideas thus
introduced are not ideas of motions of animal spirits. They are, according to II.iii.1, “Light and
Colours, as white, red, yellow, blue; with their several Degrees or Shades, and
Mixtures, as Green, Scarlet, Purple, Sea-green, and the rest … All kinds of
Noises, Sounds, and Tones … The several Tastes and Smells” as well as “Heat
and Cold, and Solidity.” On this
account, sensations are not ideas; sensations are physiological states of the
sensory nerves and brain that cause the mind to have certain ideas — those
ideas that we denominate as ideas “of” (i.e., ideas coming from) sensation. And just as the perceptions produced in
the understanding do not resemble the sensations or body motions that cause
them, so they do not — at least not obviously or necessarily — resemble
anything in the external objects that affect the sense organs. Essay
II.viii.2 is once again explicit: 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. So the properties of white and black
that we perceive as a consequence of sensation cannot be confidently affirmed
to resemble anything that exists in the outside world, at least as far as
Locke was willing to say at this point.
External objects exist in the outside world. The ideas we receive through sensation do
not even exist in our bodies or brains.
Physiological states of the sensory nerves and brain exist in our
bodies and brains. Our sense organs
and brains convey something from external objects to the mind. This conveyed item is not our ideas of
colours, heat and cold, or other qualities.
What is conveyed by the senses is rather some motion or impression. This motion or impression somehow produces
ideas of colours, heat and cold, and other qualities in the mind. So, whatever ideas may be, they are
something that arises in the mind.
They are not something that is conveyed into the mind from the
outside. They are, however, caused to
arise in the mind by something conveyed to the brain from the outside. Consequently, the extent to which there is
any resemblance between ideas and objects, or, for that matter, between ideas
and their causes in the brain, is unclear.
Locke considered this matter later, in II.viii.7-26, the topic for the
next lecture. This is not to say that Locke had a
single, clear and settled account to give of sensation. As will be seen to have been very often the
case, he was often not consistent in his views, either on this or other
important matters, and was capable of speaking in ways that convey an
entirely different picture. Consider
once again Essay II.iii.1: Thus Light and Colours, as white,
red, yellow, blue; with their several Degrees or Shades, and Mixtures, as
Green, Scarlet, Purple, Sea-green, and the rest, come in only by the
Eyes: All kinds of Noises, Sounds, and
Tones only by the Ears: The several
Tastes and Smells, by the Nose and Palate.
And if these Organs, or the Nerves, which are the Conduits, to convey
them from without to their Audience in the Brain, the mind’s Presence-room
(as I may so call it), are any of them so disordered, as not to perform their
Functions, they have no Postern to be admitted by … In this extraordinary passage, light,
colours, and the other sensible qualities are described as things that do
exist outside us and as things that are conveyed by the nerves from outside
of us into the brain, in contradiction to what must in fact be Locke’s
considered view of things. Texts that
will be examined in conjunction with the next lecture make it clear that he
could not have meant this literally.
It must be treated as a metaphorical description — one that is
particularly unfortunate for not being labeled as such and for therefore
being liable to misinterpretation. We
need to beware of this. Locke was a
sloppy writer. Just because he says
one thing in one place, it does not follow that he really meant it. We need to be sure that he did not say
something inconsistent with it somewhere else. If he did, we cannot jump to the conclusion
that he contradicted himself but must sympathetically consider things in
light of the entire corpus of his thought to try and sift out whether one or
the other pronouncement was not intended to be taken literally and what he
was ultimately trying to get at. To return to the topic, though on
Locke’s considered view ideas arise only in the mind, and are not conveyed
into it from outside, it does not follow that ideas are innate. They are not innate because they only get
produced in the mind through something else being, as Locke put it, conveyed
to the brain by the senses from objects.
Somehow — we do not know how — objects affecting the senses and so the
brain determine what ideas are produced in the mind, so that, were those
objects not to affect the senses and the brain, the ideas would simply not
arise. The mind is nonetheless so
constituted as to produce certain ideas when appropriately stimulated, and
this constitution is innate. Locke had
no quarrel with innate abilities and innate dispositions; though he did
reject ideas and judgments that are supposed to emerge out of the
constitution of the mind independently of any influence from the senses. Reflection. Locke is famous for having denied that
we have innate knowledge or innate ideas, a topic to which the first book of
the essay is largely devoted. But he
accepted that we have innate abilities, such as the ability to perceive,
remember and imagine. Some of our
innate abilities are cognitive and some conative in nature. The conative abilities produce desires and
aversions and our other passions, and the cognitive abilities modify our
ideas in various ways: by comparing them and noting marks of resemblance or
difference, by compounding or dividing them, by abstracting their common
characteristics, by applying names to them, or simply by attending to them
and leading us to become conscious of their presence. Once the mind acquires a store of ideas
from sensation, these abilities begin to operate on the ideas. Locke supposed that the mind’s
operations are transparent to it. It
need only exercise an adequate degree of attention in order to become aware
that it is performing them. This means
coming to have an idea of the particular operation it is performing. These ideas are ideas of reflection. It is important to stress that though
the operations the mind performs may be operations it is innately enabled to
perform, the ideas it forms of these operations are not innate but only
discovered by experience. This is because,
unless something first happens to the mind to arouse it to perform the innate
operations, it will never become aware of what abilities it has. The mind’s abilities only become
transparent to it through their exercise, and this requires that sensations
first come into it and create the occasion for it to exercise its abilities. Moreover, it requires that the
individual attend to what they are doing — which is something that they need
not necessarily do. Locke remarked
that many people live large parts of their lives without ever attending to
their own mental operations, and so without forming distinct ideas of them,
even though they perform them (II.i.7-8).
This is different from how things are with ideas of sensation. Whereas we are largely passive in the
reception of the latter, obtaining the former requires some action on our
part. We need to focus our attention
in a way that is not generally required for ideas of sensation. A further difference between ideas of
sensation and ideas of reflection goes unremarked. It has already been noted that when
discussing ideas of sensation Locke stressed that the idea produced by the
sensation is one thing, its cause is something else, and knowledge of the one
implies nothing about the other. Thus,
“A Painter or Dyer, who never enquired into their causes, hath the Ideas of White and Black, and other
Colours, as clearly, perfectly, and distinctly in his Understanding, and
perhaps more distinctly, than the Philosopher, who hath busied himself in
considering their Natures [i.e., the features of bodies that cause our ideas
of colours].” But it appears that, in
having ideas of perceiving, willing, remembering, discerning, desiring,
fearing, judging, reasoning, knowing, and so on, we are having ideas of those
very operations and not of something distinct from them. Having these ideas of reflection does not
involve having an “image” produced in us by causes that may in no way
resemble that image (to follow the comparison of ideas with images in a
mirror of II.i.25). It instead
consists of simply “taking notice” of the very operation itself that the mind
is performing. The mind does not “take
notice” of the very motions in the body parts that cause ideas of perception,
much less of the qualities in objects that are ultimately responsible for
producing those motions. But its ideas
of reflection are defined as “that notice which the Mind takes of its own
Operations, and the manner of them, by reason whereof, there come to be Ideas of these operations in the
Understanding” (II.i.4). Locke never
commented on this difference between ideas of sensation and ideas of
reflection. Indeed, he seems not to
have noticed it. Locke’s discussion of ideas of
reflection has anti-Cartesian implications that he remarked on over
II.i.9-19. For Locke, the mind is not
equated with the act of thinking. It
is rather described as the thing that holds ideas. It is in principle possible that the mind
could be empty of ideas (as the metaphor of blank paper at II.i.2 implies),
yet still exist. Thought, therefore,
is not the essence of the mind, as Descartes supposed, and it is not
necessary that the mind always think. Locke attempted to prove this
empirically, by claiming that there is no thought in deep sleep, even though
the mind may be supposed to persist throughout. Locke’s
Empirism. Locke claimed
that the two sources of sensation and reflection are the sole sources of our
ideas. Ideas that do not originate
from sensation or reflection are generated by acts of mind performed upon
ideas that have previously been received from sensation or reflection. However, this is not something Locke
claimed to prove with certainty. The
Cartesian idea of starting from absolutely certain first principles is one
that he rejected. But while he did not
have a proof from first principles, he did think we have good evidence for
this proposition. The evidence is of
two main sorts. Locke first claimed that there are
certain ideas that are obviously acquired from sensation. He then tried to show how all of our other
ideas could be derived from those that are obviously acquired from sensation. The second of these points is one that
Locke argued for over the course of Essay
II. To buttress his position on the
first point, the claim that there are certain ideas that are obviously
acquired from sensation, Locke appealed to our observation of children
(II.i.6 and 22), of those born lacking the use of particular sense organs
(II.ii.3, II.iii.1, and III.iv.11), and of those who have never had
experience of certain objects (II.i.6-7 and ii.2). Observation appears to indicate that there
are certain ideas that children only acquire from experience; indeed, some of
these ideas are acquired so late that we can actually remember the occasion
when we first acquired them (think of the tastes of certain wines or exotic
foods). Even more tellingly, those who
were born without the use of a particular sense organ cannot form any ideas
of the qualities specific to that sense.
Those who have been blind since birth, for example, are unable to form
any idea of colours, and even extensive discussion with those who can see is
inadequate to give them any concept of what the experience of colours is
like. A similar point holds for those who, while they have the use of all
their senses, have never had their senses affected by particular
objects. Those who have never tasted
pineapple, for example, are no more able to form a concept of this taste than
someone who has been blind since birth is able to form an idea of colour. Locke took these points to indicate that
there are certain ideas that can only be obtained through having particular
sense organs affected by particular objects, and that can in no way arise in
the absence of those objects or in the absence of the appropriate sense organs. Having established that much, it only
remained for him to argue that all of our remaining ideas are derived from
one or another set of operations performed upon these obviously acquired
ideas. Simple
and complex ideas. The ideas we get
from external sensation and reflection may be either simple or complex. They are simple when they “exhibit one
uniform appearance” (II.ii.1), that is, when they do not look to contain more
than one thing. They are complex when
they are repeated, compounded or otherwise related to one another. Examples of simple ideas are all the
individual colours in their different tints, tones, and shades; particular
smells and tastes like the smell of lily or rose and the taste of sugar;
noises, sounds and tones; feelings of hardness and softness, warmth and
coldness, smoothness and roughness, and solidity; also the ideas we have of
space or extension in general, duration in general, motion in general; and
the ideas we have of the distinct acts of the mind: believing, imagining, remembering,
willing, and so on. Complex ideas can arise from modifying
simple ideas by repeating, compounding, dividing, delimiting or comparing
them. For example, the ideas of shapes
arise from delimiting simple ideas of space, the ideas of numbers from repeating
simple ideas of numbers; the ideas of a red triangle or a turtle from
compounding simple ideas or modifications of simple ideas, and the ideas of
brightness or cause by comparing ideas. Locke remarked that our “understanding”
(i.e., imagination) can itself spontaneously repeat, compound, divide or
compare ideas to create new complex ideas, and he also claimed that our ideas
“enter by the Senses simple and unmixed” (II.ii.1). But it would be a mistake to suppose that
for Locke we receive simple ideas one after another in a stream, and that all
aggregation of ideas is due to the mind.
On the contrary, in the sentence immediately following that in which
he wrote that ideas enter by the senses simple and unmixed he stated that
“the Sight and Touch often take in from the same Object, at the same time,
different Ideas.” It would appear, therefore, that Locke
considered us to receive entire bundles or collections of ideas
simultaneously through the act of perception.
He just thought that these ideas retain their individuality so that
they can be immediately told apart from one another. Simple ideas cannot be confused with one
another (so they are perfectly clear) and, being simple, they have no parts
(so there is nothing in them that can be confused with anything else). The awareness of simple ideas therefore
constitutes the clearest and most distinct knowledge that we are capable
of. “Nothing can be plainer,” Locke
wrote, “than the clear and distinct Perception [we have] of those simple
Ideas” (II.ii.1). Over II.viii.1-6 Locke remarked on an
anti-Cartesian implication of his account of simple ideas: On his account, ideas of privative
qualities like those of black, cold, or soft, are as real and positive as any
others. There is, in other words, no
such thing as material falsity.
(Material falsity was discussed in conjunction with Descartes’s
arguments in the 3rd Meditation and at the close of the first part
of his Principles.) For Descartes, the only “simple ideas”
that are perceived with perfect clarity and distinctness are those the
understanding is supposed to be able to discern through its own inner
resources, without the aid of the senses.
Locke’s rejection of understanding as a distinct source of ideas led
him to invert Descartes’s picture. For
Locke, what is most certain and trustworthy is what our senses first tell us
about. This includes the modes of
thought (which are revealed to us by reflection) and the modes of extension
(which are revealed to us by sensation), but also all the other sensible
qualities — colours, weight, solidity, temperature, scent, and the like. The “historical, plain method” is not
concerned with uncovering what may be in the object that causes these ideas —
whether the presence of a thing or its absence — but with investigating how
that idea gets processed once it has been received. From this perspective,
even if there were “materially false” ideas produced in us by nothing at all,
they would have as real and positive a role to play as any other ideas. The idea itself is not nothing, even if its
cause might be. But Locke also had problems with the
notion that our supposedly privative ideas could in fact be caused by
nothing. If one idea (for example
heat) is caused by a certain motion in the sense organs (say high and
frequent vibration), then the opposite of that idea (cold) would be brought
about by the absence of that motion (no vibration) or by a contrary
motion. But the absence of motion is
not nothing, but rest, and a contrary motion is certainly not nothing. So as far as Locke was concerned, not only
is every idea real and positive, but the causes of ideas must be real and
positive as well. Solidity. Locke singled out the idea of solidity
for special attention, identifying it as the idea that “seems the ... most
intimately connected with, and essential to body” (II.iv.1). This is something of a startling claim if
we think that the idea of solidity is an idea of sensation and recall what
was said earlier about the distinction Locke otherwise drew between perceiving
an idea of sensation and knowing what it is about the nature of objects that
is the ultimate cause of that idea.
But there are yet more incongruous features to Locke’s account of
solidity. He maintained that it is
impossible to define a simple idea of sensation. If anyone is unfamiliar with some simple
idea we are talking about, such as the colour red, all we can do is expose
them to the circumstances that will cause them to have that idea. We cannot otherwise explain what the idea
is (II.iv.6, cf. III.iv.11).
Occasionally, Locke treated solidity as just such a simple idea,
claiming that if anyone asks what solidity is, we must send them to their
senses to inform them (II.iv.6). This
is just what we would expect if solidity is an idea produced in us by touch
or the product of a tactile sensation.
As so understood solidity would be a particular feeling we experience
when we run into something — a feeling that can vary from the feeling of a
prick or pressure point to acute pain.
But elsewhere, Locke gave a very precise definition of solidity,
something that should be impossible if it is just a feeling. He defined it as the idea of resistance to
penetration. Supposedly, this is an
idea that we get through our sense of touch when we approach a body and find
that it does not allow us to enter the space it occupies. As such, it is a far from simple idea,
involving just “one uniform appearance.”
It is instead a complex made up of ideas of motion, collision, and the
consequences of collision, apparently including the idea of “resistance” to
compression and so the idea of what is in effect a repulsive force — a force
or power to resist motion in a certain direction. Even more extraordinarily, it is not a
feeling produced in us as a consequence of tactile sensation. It is a quality of a body that resides in
that object. Locke seems not to have realized that he
was speaking of “solidity” in two different ways, as a simple and indefinable
feeling produced in us by touch, and as a body’s quality of exercising a
repulsive force to prevent other bodies from entering the space that it
occupies. Not surprisingly, therefore,
it is far from clear how we are supposed to get the latter idea. Does the experience of the tactile feeling
somehow lead us to infer or intuit that we are encountering a body that is
exercising a repulsive force? Does the
experience involve the sort of direct awareness of this quality in bodies
that is involved in obtaining ideas of reflection? Locke never said. It is simply not obvious how Locke’s
account of the idea of solidity fits with his official position on sensations
as motions of body parts and ideas of sensation as perceptions of images
produced in the mind as a consequence of the nerves conveying motions to the
brain. Setting this aside, Locke distinguished
the idea of solidity from that of hardness.
Whereas solidity has to do with repulsion, hardness has to do with
attraction or cohesion. When the parts
of a body attract one another or cohere together so strongly that they resist
our attempts to move them relative to one another, we say the body is
hard. But very soft bodies, such as
water, can still be solid, in the sense of resisting compression. Locke considered hardness to be something
that comes in degrees and is relative to our own strength. The stronger we are, the sooner we can make
the parts of a body move relative to one another and the softer we consider
it to be. But solidity is something
Locke assumed to be absolute. It does
not come in degrees but is always entirely present. He did not believe, as we do today, that it
is in principle possible to go on compressing materials forever to produce
denser and denser things like neutron stars or black holes. Instead, like Whether
we move or rest, in whatever posture we are, we always feel something under
us that supports us and hinders our further sinking downwards, and the bodies
[that] we daily handle make us perceive that, while they remain between them,
they do by an insurmountable force hinder the approach of the parts of our
hands that press them. [II.iv.1] It is in part because of this absolute
nature (most other qualities come in degrees) that Locke considered solidity
to be the idea that “seems the ... most intimately connected with, and
essential to body” (II.iv.1). In fact,
he speculated at Essay II.iv.5 that
inertial force (“impulse”), cohesion, and hardness may simply be modes of
solidity. In opposition to Descartes,
he maintained that wherever we think there is some body, that is, some
material thing, we also think there is resistance or solidity. In making this claim, Locke was staking out
a very different position on our idea of the essential nature of body. Rather than say that our idea of body is
just an idea of a shaped and movable piece of extension, Locke insisted that
it requires something more: the additional idea of solidity or
impenetrability — the idea, in other words, of repulsive force. Remove this idea of solidity from the idea
of an extended body and it ceases to be an idea of body and becomes an idea
of empty space. Thus, for Locke, unlike for Descartes,
there is a distinction to be drawn between the ideas of space and of
body. The idea of body is the idea of
a solid, divisible, and movable extension.
The idea of space is the idea of a penetrable, indivisible and
immovable extension. We think that
bodies sit in space, which they penetrate perfectly and move through. We think that space and all its parts are
immobile, so that no part can be moved out of the vicinity of its
surroundings and space itself cannot be divided or broken. Locke justified this position on body
and space by appeal to experience.
Whenever our experience supplies us with an idea of something that we
consider to be a body, he claimed, we also find that it supplies us with the
idea of solidity. Descartes had tried
to undermine this view with the argument of Principles II.4 and II.11, where he had claimed that if all bodies
retreated from our hands when we attempted to touch them, we would still have
an idea of body. But Locke could have
replied that the thought experiment only proves that we can conceive of
bodies without having to conceive them to be hard, not that we can conceive
of them without having to conceive of them to be solid. Solidity is the property of resisting
penetration, and if bodies retreat from our hands as we approach them that
does not mean that they are not solid.
After all, as long as they retreat from our hands, the test to
determine whether they resist penetration has only been confirmed, not
disconfirmed. If they were not solid,
they would not retreat but would allow our hands to pass through them like mist. Locke could have asked what would happen if
there were an immovable wall just behind the bodies we reach out for. Would they retreat through the wall? Then there would be two bodies in one place
at the same time, which Descartes would hardly accept. Would they allow our hands to penetrate
their dimensions? Then we would not
think they are bodies, but empty space. Or would they resist the motion of
our hands with “an insurmountable force?”
Then solidity, and not just extension, is essential to body. Neither was Locke convinced by Descartes’s
arguments against empty space. For Locke, if you remove all solid, movable
extension from a container, there will still be something, namely penetrable
immovable extension, left over between its walls, and therefore the walls
will not be together. Locke reiterated these points, and
supplemented them with further arguments in favour of the existence of a
vacuum, over Essay II.xiii.11-27. Locke’s position on these matters was
seconded by ESSAY
QUESTIONS AND RESEARCH PROJECTS
1. Critically
assess Locke’s argument for empirism, as presented
over Essay II.i.5-7, ii.2-3, iii.1
and III.iv.11.
2. In the
mid-eighteenth century the French philosopher, Etienne Bonnot,
Abbé de Condillac, argued
that Locke had been too moderate in his empirism
insofar as he had allowed that we might be innately capable of performing
certain operations on our ideas and obtaining “ideas of reflection” from
reflecting on those operations.
According to the argument of Condillac’s most famous work, the Treatise on sensations, we learn to
perform all mental operations through having our attention focused in certain
ways as a consequence of the experience of pleasure and pain. Study Condillac’s work and explain whether
his “sensationist” reply to Locke is ultimately
successful.
3. Locke’s position
on the distinction between body and space was a controversial one, and many
philosophers in addition to Descartes found it difficult to accept. He offered further arguments for it in a
chapter specifically devoted to space, Essay
II.xiii.
Some of the principal arguments against the possibility of empty space
were articulated by Pierre Bayle in note I of the article on “Zeno of Elea”
from his Historical and critical
dictionary (Richard H. Popkin, trans.
[Indianapolis: Hackett, 1991], pp.377-385), with specific reference to
Locke’s inability to defend his position with anything more than objections
to the contrary position. |
