An Essay Concerning Human
Understanding
John Locke
§1 Since it is the understanding that sets man above all other animals and enables
him to use and dominate them, it is certainly worth our while to enquire into it.
The understanding is like the eye in this respect: it makes us see and perceive all
other things but doesn’t look in on itself.
I. 1. §2 I shan’t involve myself with the biological aspects of the mind. For
example, I shan’t wrestle with the question of what alterations of our bodies lead
to our having sensation through our sense-organs or to our having any ideas in
our understandings. Challenging and entertaining as these questions may be, I
shall by-pass them because they aren’t relevant to my project. All we need for my
purposes is to consider the human ability to think … Someone observing human
opinions from the outside—seeing how they conflict with one another, and yet
how fondly they are embraced and how stubbornly they are maintained—might
have reason to suspect that either there isn’t any such thing as truth or that
mankind isn’t equipped to come to know it.
I. 1. §3 So it will be worth our while to find where the line falls
between opinion and knowledge, and to learn more about
the ‘opinion’ side of the line. What I want to know is this:
When we are concerned with something about which we have
no certain knowledge, what rules or standards should guide
how confident we allow ourselves to be that our opinions
are right? Here is the method I shall follow in trying to
answer that question. First, I shall enquire into the origin of
those ideas or notions—call them what you will—that a man
observes and is conscious of having in his mind. How does
the understanding come to be equipped with them? Secondly,
I shall try to show what knowledge the understanding has by
means of those ideas—how much of it there is, how secure it
is, and how self-evident it is. I shall also enquire a little
into the nature and grounds of faith or opinion—that is,
acceptance of something as true when we don’t know for
certain that it is true.
I. 1. §4 I hope that this enquiry into the nature of the understanding will enable me
to discover what its powers are—how far they reach, what things they are
adequate to deal with, and where they fail us. If I succeed, that may have the
effect of persuading the busy mind of man •to be more cautious in meddling with
things that are beyond its powers to understand; •to stop when it is at the extreme
end of its tether; and •to be peacefully reconciled to ignorance of things that turn
out to be beyond the reach of our capacities.
§6 It is very useful for the sailor to know how long his line is, even though it is too
short to fathom all the depths of the ocean.
I.I. §8 Before moving on, I must here at the outset ask you to excuse how
frequently you will find me using the word ‘idea’ in this book. It seems to be the
best word to stand for whatever is the object of the understanding when a man
thinks; I have used it to express whatever is meant by ‘phantasm’, ‘notion’,
‘species’, or whatever it is that the mind can be employed about in thinking; and I
couldn’t avoid frequently using it. Nobody, I presume, will deny that there are
such ideas in men’s minds; everyone is conscious of them in himself, and men’s
words and actions will satisfy him that they are in others. First, then: How do they
come into the mind?
I. 2, §4 Children and idiots have no thought—not an inkling—of these principles [e.g.
It is impossible for the same thing to be and not to be], and that fact alone is enough
to destroy the universal assent that any truth that was genuinely innate would have to
have. For it seems to me nearly a contradiction to say that there are truths imprinted
on the soul that it doesn’t perceive or understand—because if ‘imprinting’ means
anything it means making something be perceived: to imprint anything on the mind
without the mind’s perceiving it seems to me hardly intelligible. So if children and
idiots have souls, minds, with those principles imprinted on them,
they can’t help perceiving them and assenting to them … It may be said that a
proposition that the mind has never consciously known may be ‘in the mind’ in the
sense that the mind is capable of knowing it; but in that sense every true proposition
that the mind is capable of ever assenting to may be said to be ‘in the mind’ and to be
imprinted!
Why, according to Locke, is Nativism [belief in innate ideas] not only unnecessary but
illegitimate? One prominent theme is that if there were innate principles in the
mind—his example is Whatsoever is, is—we would be aware of them, and they would
therefore be universally assented to. But, he argues, children and idiots cannot even
make sense of such claims, let alone assent to them. He goes on to argue that various
fallback positions—assent when they understand, assent when they begin to reason,
capacity to assent under appropriate conditions—all reduce the claim to a sort of
triviality. The upshot is that innateness is either a real alternative to Empiricism but
obviously false, or trivially true but not incompatible with Empiricism.
http://plato.stanford.edu/entries/innateness-history/#EmpAttNatLocHum
Underlying much of Locke's attack is the Cartesian view that to claim something is ‘in
the mind’, innately or not, is to give it a place in our conscious awareness. Leibniz's
bold hypothesis of non-conscious mental states would, if successful, sweep aside most
of Locke's arguments against innateness. But we need to keep in mind that the
polemics in the Essay, though they were historically influential, are almost a sideshow.
The real issue is whether the Empiricist can construct a satisfactory account of human
knowledge without adverting to any innate ideas and principles. To meet this
challenge, Locke (and to an even greater extent Hume) offered what may be termed
adequacy of the stimulus counterarguments.
II.1.6 Everyone is conscious to himself that he thinks; and when thinking is
going on, the mind is engaged with ideas that it contains. So it’s past doubt that
men have in their minds various ideas, such as are those expressed by the
words ‘whiteness’, ‘hardness’, ‘sweetness’, ‘thinking’, ‘motion’, ‘man’, ‘elephant’,
‘army’, ‘drunkenness’, and others. The first question, then, is How does he
acquire these ideas? It is widely believed that men have ideas stamped upon
their minds in their very first being. My opposition to this in Book I will probably
be received more favourably when I have shown where the understanding can
get all its ideas from—an account that I contend will be supported by
everyone’s own observation and experience.
II.1.§ Let us then suppose the mind to have no ideas in it, to be like white paper with
nothing written on it. How then does it come to be written on? From where does it
get that vast store which the busy and boundless imagination of man has painted on
it—all the materials of reason and knowledge? To this I answer, in one word, from
experience.
II.16.§1 Among all the ideas that we have, none is •suggested to the mind by more
ways, and none is •more simple, than the idea of unity or one. It •hasn’t a trace of
variety or composition in it; and •every object that our senses are brought to bear
on, every idea in our understandings, every thought of our minds, brings this idea
along with it. This makes it the most intimate to our thoughts, and also the most
universally applicable idea that we have. For number applies itself to men, angels,
actions, thoughts, everything that exists or can be imagined …
§5 By repeating the idea of a unit, joining it to another unit, we make one collective
idea marked by the name ‘two’. If someone can do this, and can carry the procedure
further by adding one to each collective idea that he reaches, and also gives a name
to every number whose idea he comes to, then he can count.
1. If you want to know what kind of idea it is that we name ‘infinity’, you can’t do
better than to consider •what the idea of infinity is most immediately applied to by the
mind, and then •how the mind comes to form this idea. Finite and infinite seem to me
to be viewed by the mind as modes of quantity, and to be attributed primarily and
initially only to things that have parts, and can be augmented or diminished by the
addition or subtraction of parts, however small.
§3 Someone who has an idea of some stated length of space finds that he can repeat
it, going from the idea of one foot (say) to that of two feet, and that by further
addition he can go to three feet, and so on without ever reaching an end of his
addition. This holds good whether he started with the idea of a foot, or of a mile, or
of the diameter of the earth. Whatever he starts with, and however often he
multiplies it, he finds that however far he has gone he has no more reason to stop—
and isn’t one jot nearer the end—than he was when he set out. From this he takes
the idea of infinite space.
§4. That account of the source of the idea of infinite space doesn’t settle whether
there actually exists a boundless space answering to the idea, because our ideas
aren’t always proofs of the existence of things.
II.20.§6 Among the simple ideas that we receive from both sensation and reflection,
pain and pleasure are two very considerable ones. •Bodily sensations may occur
alone or accompanied by pain or pleasure; and •the thoughts or perceptions of the
mind may also occur solo or else accompanied by pleasure or pain, delight or trouble,
call it what you will. Like other simple ideas, these two can’t be described, nor can
their names be defined; the only way to know them is by experience. A ‘definition’ of
them in terms of the presence of good or evil makes them known to us only by
making us reflect on what we feel in ourselves when we think about or undergo
various operations of good and evil.
Two things fill the mind with ever new and increasing admiration and awe, the
more often and steadily reflection is occupied with them: the starry heaven above
me and the moral law within me. Neither of them need I seek and merely suspect
as if shrouded in obscurity or rapture beyond my own horizon; I see them before
me and connect them immediately with my existence.
- Immanuel Kant, Critique of Practical Reason
Fish can distinguish between larger and smaller quantities, with an additional ability to
"count" up to three, according to research on tropical angelfish.
Angelfish are regarded as being one of the world's most intelligent fish, but scientists
believe other fish species also possess the math-related skills outlined in a new Animal
Cognition paper.
Doing something akin to counting up to three might sound underwhelming, but math
itself is a very human-centric concept that may need reconsideration if comparisons
are to be made with the abilities of non-human species.
"We all think we know what we mean by 'counting,' but do we really?" asked coauthor Robert Gerlai. "Is recounting a series of 1 to 100 counting? Is 2+3=5 counting?
Is calculating the square root of a number counting, or perhaps is the mathematics
necessary for quantum physics counting?”
http://news.discovery.com/animals/angelfish-counting-math-110109.html
"The point is that even within our own species, mathematical abilities vary
tremendously," Gerlai, a University of Toronto Mississauga professor of psychology, told
Discovery News. "So far, most biological, including behavioral, traits we initially believed
to be unique properties of our own species have turned out to have some homologues
in animals.”
Gerlai and Luis Gomez-Laplaza of the University of Oviedo in Spain exploited the
previously determined tendency of angelfish to seek protection in unfamiliar
environments by joining the largest possible fish group, called a shoal. To rule out
possible confounding effects arising from sexual interactions, the researchers only used
juvenile angelfish for their experiments.
Test fish placed in special compartmentalized tanks were given a simultaneous choice
between shoals containing different numbers of fish. The angelfish were always able to
select the larger of two groups so long as the ratio between the shoals was 2:1 or above.
Below that ratio, their choices were less predictable, suggesting a limit to their quantity
estimation abilities.
After the findings were published, the researchers, according to Gerlai, "have already
collected new data suggesting that angelfish can discriminate much more precisely than
this. That is, angelfish can tell the difference between 3 and 2, for example."
He added, "This ability does resemble 'counting' individual items as opposed to
estimating quantities, but this counting ability does not extend beyond three."
To make our difficulties plain, let us concentrate attention on the
table. To the eye it is oblong, brown and shiny, to the touch it is
smooth and cool and hard; when I tap it, it gives out a wooden
sound. Any one else who sees and feels and hears the table will
agree with this description, so that it might seem as if no difficulty
would arise; but as soon as we try to be more precise our troubles
begin. Although I believe that the table is ‘really’ of the same
colour all over, the parts that reflect the light look much brighter
than the other parts, and some parts look white because of
reflected light. I know that, if I move, the parts that reflect the
light will be different, so that the apparent distribution of colours
on the table will change. It follows that if several people are
looking at the table at the same moment, no two of them will see
exactly the same distribution of colours, because no two can see
it from exactly the same point of view, and any change in the
point of view makes some change in the way the light is reflected.
– Russell, The Problems of Philosophy
For most practical purposes these differences are unimportant,
but to the painter they are all-important: the painter has to
unlearn the habit of thinking that things seem to have the
colour which common sense says they ‘really’ have, and to learn
the habit of seeing things as they appear. Here we have already
the beginning of one of the distinctions that cause most trouble
in philosophy – the distinction between ‘appearance’ and
‘reality’, between what things seem to be and what they are.
The painter wants to know what things seem to be, the practical
man and the philosopher want to know what they are; but the
philosopher’s wish to know this is stronger than the practical
man’s, and is more troubled by knowledge as to the difficulties
of answering the question.”
They [the experimental subjects] watched two separate sets of Hollywood movie
trailers, while fMRI was used to measure blood flow through the visual cortex, the part
of the brain that processes visual information. On the computer, the brain was divided
into small, three-dimensional cubes known as volumetric pixels, or “voxels.”
“We built a model for each voxel that describes how shape and motion information in
the movie is mapped into brain activity,” Nishimoto said.
The brain activity recorded while subjects viewed the first set of clips was fed into a
computer program that learned, second by second, to associate visual patterns in the
movie with the corresponding brain activity.
Brain activity evoked by the second set of clips was used to test the movie
reconstruction algorithm. This was done by feeding 18 million seconds of random
YouTube videos into the computer program so that it could predict the brain activity
that each film clip would most likely evoke in each subject.
Finally, the 100 clips that the computer program decided were most similar to the clip
that the subject had probably seen were merged to produce a blurry yet continuous
reconstruction of the original movie.
Reconstructing movies using brain scans has been challenging because the blood flow
signals measured using fMRI change much more slowly than the neural signals that
encode dynamic information in movies, researchers said. For this reason, most
previous attempts to decode brain activity have focused on static images.
“We addressed this problem by developing a two-stage model that separately
describes the underlying neural population and blood flow signals,” Nishimoto said.
Ultimately, Nishimoto said, scientists need to understand how the brain processes
dynamic visual events that we experience in everyday life.
“We need to know how the brain works in naturalistic conditions,” he said. “For that,
we need to first understand how the brain works while we are watching movies.”
http://newscenter.berkeley.edu/2011/09/22/brain-movies/