|
4 Hobbes, Human nature I-III, De Corpore 25.2-3,5-7,9
[Hobbes,
Human nature, Introduction] Hobbes was the
individual in the seventeenth century who did more than anyone else to give
the mechanical philosophy a bad name.
This is something he did, not by attacking the claims of the
mechanical philosophy, but by taking it to extremes, and applying it to
themes most mechanical philosophers did not want to touch. While mechanical philosophers like Boyle
described the mechanical philosophy as the view that all the phenomena of
nature are produced by the motion and impact of bodies, they meant to
restrict the thesis specifically to outer
nature, that is, the nature of the world around us. Hobbes took the thesis a step further and
applied the mechanical philosophy to inner
nature as well, that is to the nature of human beings, their mental
processes, and the causes of their actions.
Rather than take cognitive and conative operations like sensation, reasoning,
and will to be exercised by a soul or spirit that feels and reasons about
what is best, Hobbes took these operations to be the products of a machine,
working just in accord with the laws of motion and collision. Hobbes meant to appeal
to this account of human nature to justify a system of politics. As he observed in the letter of dedication
to the Earl of Newcastle that prefaces the work, one cannot hope to justify a
system of politics by talking about political systems. One instead needs to justify it by talking
about human nature. As long as we
confine ourselves to talking about political systems, people will perceive
where their own self-interest lies, and will never recognize an argument for
a political system that is contrary to their interests. But such contentions cannot arise in what
Hobbes referred to as “mathematical” topics, which include the consideration
of geometry (how bodies fill space and so acquire shape) and mechanics (how
shaped bodies move over time). Not
only are the fundamental elements involved in these sciences so clear as to
be free from any possibility of disputation, but people’s passions are not involved
in them. There are no self-interests
to be served by contenting that a geometrical or mathematical truth must turn
out to be a certain way. Given that
this is the case, if we can establish that human beings are just machines
consisting of arrangements of shaped and moving parts that behave as they do
as a consequence of laws of motion and collision, then we ought to be able to
lead people, by clear and indisputable steps, from a theory of mechanics to a
theory of human nature and in incontestable account of what makes people act
as they do in society. Given such a
mechanistic understanding of human nature, the consequences for how to
construct a well-functioning society would follow as obviously as the design
of a machine follows from a consideration of the effects it needs to bring
about. In the selection from Human nature I-III, Hobbes launched
this project by first challenging the traditional, Aristotelian notion that
there are two distinct cognitive faculties, a lower or sensory faculty,
responsible for perception, memory, imagination, and anticipation, and a
higher or intellectual faculty, responsible for grasping universal concepts,
judgment, and reasoning. In opposition
to this view, Hobbes reduced the cognitive operations of the mind to a single
operation, conception or conceiving.
He argued that all conception originates with sensory experience (HN
II.2) and attempted to show that all the other operations of the mind are
simply outgrowths from sensory experience.
Sensory experience itself is a purely mechanical effect on the
body. Sensible qualities not only have
no external existence, but no internal existence either. What exists in us
when we have sensations is not colours or feelings of warmth and cold, but
merely motions of the parts of our sense organs and central nervous
system. Sensible qualities are simply
the way these motions appear to us. QUESTIONS ON THE
1. What is
sense? Reading Note on II.4:
“visible and intelligible species,” which are “worse than any paradox.” If you have purchased Gaskin’s print
edition of our Hobbes selections, you will notice asterisks in the text. These mark Gaskin’s own explanatory notes,
which are collected at the back of the book, and which are always helpful and
worth reading. An advantage of
purchasing the printed books is that they contain this sort of editorial
material, specifically designed to help students master the reading. Gaskin’s introduction is also worth reading
(like the introductions to all the print editions). In this case, a few extra comments are called
for. The accepted theories of
perception of Hobbes’s day held that we directly perceive external objects
more or less exactly as they are. But
since the objects perceived in vision, smell, and hearing are at some
distance from us, this poses a problem.
How do we manage to perceive the object given that it is not in
contact with our sense organs? The
standard answer was that objects emit something, called a “sensible species”
(or, in more modern English, a “sensible likeness”) that flies through the
air between them and us to affect our sense organs. But while this works well enough for smell,
where we have no problem conceiving the object as a kind of source or
fountain of a characteristic scent that it emitted through the surrounding
air and taken up in smell, it starts to seem clumsy when offered as an
account of sound, and it is nothing less than “worse than any paradox” as
Hobbes observed, when applied to account for vision. As Hobbes observed, we see shaped
colours. Does that mean that objects
must be constantly shedding shaped colours off of their surfaces, like snake
skins, and sending them flying through the air towards our eyes? Wouldn’t the shaped colour carcasses from different
objects get in another’s way? How
could they pass whole and entire into the eye, given that the holes of the
pupils are so small and the objects are often so much larger? Wouldn’t the objects have to be sending
millions and millions of these carcasses off at once in all directions in
order to be simultaneously visible from various different positions over long
periods of time and wouldn’t that mean that they would have to rapidly loose
all their stuffing and shrink to nothingness?
These are the sort of “paradoxes” that affect the theory and that
Hobbes was alluding to.
2. What is
colour, and where is it to be found?
3. What
convinced Hobbes that colours and images do not exist outside of us?
4. What leads
us to mistakenly believe that light and sound are outside of us?
5. Why do our
sensations remain with us after the bodies causing them have ceased to press
on our organs, and why do they only slowly fade away?
6. If our
sensations stay with us after the bodies causing them have ceased to press on
our organs, why are we not aware of them?
7. What is the
cause of dreams?
8. How did
Hobbes define the notions of obscurity and clarity of conception?
9. How does
remembrance differ from sensing? NOTES ON THE a.
Arguments against
the real existence of sensible qualities. Unlike Galileo, who
only sought to show that there are advantages to the hypothesis that the
sensible qualities have no existence outside of the bodies of sentient
creatures, Hobbes was more emphatic in his denial and sought to show that
there are strong reasons for rejecting the view that sensible qualities have
any sort of real existence, either in things or even in the bodies of
sentient creatures like ourselves. His arguments for this
thesis, offered over HN II, are multiple and
interrelated. One argument, an
argument that can be called the hedonic state argument, is used to establish
the unreality of our tactile sensations of heat and cold. According to this argument, our feelings of
heat and cold are mixed up with feelings of pleasure and pain. But pleasure and pain only exist in
sentient creatures. Therefore, the kind of qualities we know when we talk
about heat and cold can only exist in sentient beings (HN II.9). A second argument, the
perceptual relativity argument, is used to establish the unreality of our
sensations of taste and smell. According
to this argument the same object can taste or smell differently to two
different people. The taste or smell
that at least one of these people experiences cannot therefore be in the
object but must be something brought about only in that person. And as long as we have no reason to suppose
that either person has defective sense organs, and every reason to suppose
that the senses function in more or less the same way in both, we have every
reason to suppose that if what the one is experiencing is not a real state of
the object neither is what the other is experiencing. Both are most likely experiencing effects
that the object is having on their own bodies, rather than the object itself
(HN II.9). This is a classic argument,
which draws inspiration from the ancient sceptical “modes” of proving that we
cannot get knowledge of things as they are in themselves through our senses. However, by far the
most important of Hobbes’ arguments is an argument based on a careful
empirical investigation of the causes of visual and auditory sensation. This argument not only establishes that
sounds and coloured shapes do not exist outside of us, but also that what
does exist outside of us is just a motion of silent, colourless particles
that are quite differently shaped from the colour patches we actually see,
and the sounds we actually hear.
(Interestingly, Hobbes’ argument establishes that the shapes that we
see are unreal, as well as the colours, though he does not trumpet this result.)
To make his case,
Hobbes first observed that shaped colours and sounds often appear outside of
the objects that they are supposed to inhere in. This is the case with sounds bouncing off
walls, reflections in mirrors, and the real images cast by panes of glass
(think of looking out a window into a darkened street at night and seeing the
reflection of the illuminated room behind you as if it existed out in the
street). This evidence is not adequate to lead us to infer that colour
patches and sounds do not also inhere in objects, but it does show that the
two are not necessarily coincident (HN II.5). To strengthen his case
Hobbes appealed to a further piece of evidence: As a student of optics, he knew that if I
focus my eyes on objects at a certain distance, say on a finger held up
before my eyes, the objects before and behind the focal plane will appear
doubled. (Hold up a finger, focus on it, and if you keep it in focus you will
notice that objects towards the back of the room behind it appear
doubled.) Our sense of touch and other
visual experiences tell us that the objects in the room are not doubled, and
we can make the doubled images come and go by an act of will, by choosing to
focus our eyes in a certain way. This
suggests that at least one of the double images is not located where the
object is. But the images are
identical. Any reason we have to think
that one of them is located somewhere outside of the object is as good a
reason to think that the other is as well.
Since we do have good reason to think one is located outside of the
object, we have good reason to think that both are. Pursuing his case yet
further, Hobbes went on to claim that not only do colours and sounds not
inhere in the objects that cause them, they do not even inhere in the places
where they appear to us to be. The
images reflected in a mirror appear to be behind the mirror, but experience
readily confirms that this is not in fact the case. The colour reflected from the surface of
the water appears to be in the water, but if you spoon some of the water up you
will see that this is not the case and that the water is not really coloured
like that at all. The colours
projected out into the street by the darkened window are not really out
there, either, and so on (II.6) Hobbes had a yet more
decisive point to make. Experiments
show that our experiences of colour are not produced by colour, but by
impact. A blow to the eyes causes us
to see stars. Someone sitting in a
darkened room, where there is nothing coloured that could possibly affect the
eyes, and who receives a blow to their eyes, will see colours. Hobbes took this to be a crucial experiment
demonstrating that impact produces our sensations of colour (II.7). This is even more apparent in the case of
sound since we know a blow of some sort is required to produce a sound (HN
II.9). This evidence has a
striking consequence. If the cause of
vision and of hearing is a blow, then it is most plausible to suppose that
the effect this cause has on us is a motion in the parts of our sense organs,
sensory nerves, and brain. Hobbes did
not neglect to remark on this. “From
[this] experience we may conclude,” he wrote, “that apparition of light without, is really nothing but motion within” (HN
II.7). And further: “The air imparteth motion by the ear and nerves to the brain; and
the brain hath motion but not sound” (HN II.9). So not only do colour
and sound not exist in objects or in the space between us and objects, they
do not even exist in us. What exists
in us is actually just a motion. Building on this evidence,
Hobbes proceeded to construct a theory of light and colour. Unlike Galileo, who suggested that light
might be caused by an explosion of ignicoli flying
out through the air, Hobbes took light to be the product of a pulse,
producing a chain reaction or a wave.
After all, he observed, fire appears to pulsate or flicker and when
this pulsating motion is prevented by enclosing the fire in a tight space it
dies. (Today we think this happens
because the fire cannot get any oxygen, but to Hobbes’ mechanical mind the
fire dies due to the prevention of motion.)
Nothing is actually emitted from the flame. Instead, the pulse from
the flame hits the parts of the surrounding air, which in turn hit the parts
that surround them, and so on, producing a wave in the air that propagates
outwards. Sometimes these waves will
travel directly from the fire or the sun or some other luminescent object to
the eye. At other times, they will
bounce off some smooth surface before hitting the eye, and at yet other times
they will bounce off some irregular surface that significantly changes the
character of their motion. This
accounts for the difference between seeing pure or white light (no bounce),
reflections (bounce from a smooth surface) or colours of various sorts
(bounce off of various sorts of irregular surface). When the wave hits the
eye, it has the same effect on the parts of the eye and the optic nerve that
the fire had on the air. Parts that
have been hit rebound back, hitting the parts behind them and making them
recoil, and so on. A pulse or wave is
sent through the eye and travels up the optic nerve towards the brain. The same thing happens
with sound, except that in this case the pulse, caused by percussion of one
object on another, travels through the air to the ear and then on to the
brain. These claims raise a
number of questions. If colours and
sounds do not exist in objects, or in the space between us and objects, or
even in us, and if all that actually exists in us when we see or hear is some
motion in the brain, then where to colours and sounds exist, why do we think
we experience them, and why do we suppose that they exist outside of us? Hobbes’ answers to
these questions are rather perfunctory.
Just as the rainbow, which is really a collection of microscopic water
droplets reflecting sunlight, appears to us from a distance as a band of
colours, so Hobbes seems to have thought that the minute motions in our
brains “appear” to us as colours and sounds.
We take these colours and sounds to be outside us because, as a pulse
or wave of motion travels inwards towards the brain, it encounters increasing
resistance from the densely packed parts of the nerves and brain, which do
not recoil easily and which are quickly pressed back by the parts behind
them. As a result, a
recoil occurs. The inner parts
of the brain, having been pushed back by the inward sensory pulse, rebound in
the opposite direction, pushing now on the parts in front of them, creating
an outward pulse of motion traveling back along the sensory nerves. It is only when the motion starts
travelling back in the outward direction that it starts to look to us like a
sensation (prior to that it is an unsensed cause of
sensation). Because we sense that the
pulse or wave of motion is traveling in an outward direction, we take the
line of its motion, which points outwards from us, to be pointing to a place
somewhere outside of us and mistake the sensation for something that exists
at that place outside of us. This is not a very
satisfying account. It raises more
questions than it answers. Who is the
“us” to whom brain motions appear as colours and sounds? If all that exists in the brain is a
motion, then is there some other part of us behind the brain that is looking
at the brain and confusedly seeing the motions in the brain as colours and
sounds? If so, what and where is this
thing and how it is related to the brain? And how can a motion, however small
or confused, possibly appear as a colour or sound? Hobbes seems to have
found these questions uninteresting.
It was enough for him to be able to establish, on what he took to be
good grounds, that what is outside us is just a shaped object in motion and
that the most direct effect of this object is a motion in our sense organs,
central nervous system, and brain.
Supposing that Hobbes could go on to tell a story just about these
internal, physiological motions and how they produce the other cognitive and
conative phenomena of human nature, he would have developed the theory as far
as he needed to go and could afford to ignore the further questions. b.
Memory, imagination and dreams.
Hobbes proceeded to do just that and to extend his mechanical account
to other cognitive phenomena. He
claimed that once sensations have been produced they reverberate in the brain
for an indeterminate length of time, slowly diminishing in strength (due to
the ongoing resistance of the parts of the brain) as they do so. The motions will typically occur in a
chain, having been preceded by other motions and being followed by yet
others. Like images, these chains of
motions have parts. As the motions in a chain diminish in strength, the
little motions that are parts of the chain fade, run into one another, and
become confused. Confused motions are
like images of objects seen at a distance, where their smaller parts cannot
be distinguished from one another. Hobbes appealed to
these notions in order to account for memory.
As far as he was concerned, in both sensation and memory a particular
motion is now (presently) occurring in the brain. He had little choice over this. After all, if the motion is past, it no
longer exists, and if it no longer exists it cannot be what accounts for the
fact that I am now remembering. But if
the motion is present, what distinguishes it from a sensation? Hobbes explained that it will often be the
case that when we first see something, we obtain a very distinct conception
of it with all of its parts. Then,
later, when this image has faded and become indistinct, we look at it and
note that it does not contain as much information as it formerly did. This experience, of looking at an image to
find some information we were previously able to obtain from it, and
discovering that it no longer contains that information, is what leads us to
identify the representation as a memory and prevents us from confusing
memories with present experiences. In
all cases of remembering, we always are aware of the indistinctness of our
representation as compared to what we experienced in the past. We think we are missing something. Unfortunately, this
account of memory is question begging.
Unless I am able to remember what the past image was like, I can’t
compare it with my current representation and judge that the current
representation is indistinct and lacks something that was present in my past
representation. So I need to be able
to remember in some other way than the way Hobbes described in order to
remember in the way he described — which is to say that Hobbes simply failed
to account for memory. At HN III.6 Hobbes
wrote that we “take notice” of objects outside of us and that this is what
having a conception amounts to. The
outward reaction to a motion produced in us by the senses is our “taking
notice” of an object. But then he went
on to add that “we take notice also some way or other of our
conceptions. For when the conception
of the same thing cometh again, we take notice that it is again; that is to
say, that we have had the same conception before.” And he went on to declare, “This therefore
may be accounted a sixth sense.” There would be no
circularity in claiming that we have some further, special ability to recognize
a conception we now have to be one we have had before. The problem is that Hobbes did not have the
resources to account for any such operation.
The words he chose indicate he was beyond his reach: “we take notice
some way or other of our conceptions.”
Some way or other, indeed. If
the notice we take of objects is a conception, what would the notice we take
of our conceptions be? A conception of
a conception? And if a conception is
just an outward rebound of a motion produced in us by our senses, what would
a conception of a conception be? The
last thing Hobbes would want to do is recognize the existence of some mental
entity that experiences sensations and then remembers those experiences. The whole project is to reduce such
operations to mechanical operations of body parts. Accordingly, in the immediately following
HN III.7 we are presented with an account of “the manner by which we take
notice of a conception past” and that account is one that appeals to the
occurrence of a present conception
that is more obscure than some past one, supplemented by the question-begging
appeal to an ability to “remember” what the past one was like and so notice
that the present one is not as clear as the past one was. Hobbes was more
successful at accounting for imagination and dreaming. He supposed that, just as the links in a
chain of motions can fade and melt into one another as the motions fade, so,
when a number of motions are simultaneously banging around in the brain, they
can bang into one another, mix, and produce a sort of compound motion that is
a product of the mixing of many others, like waves from many different
directions coming together and producing a compound wave. If the motions are again thought of as
chains that make up images (that is, things with partial motions set outside
one another), then the “images” that are produced will be a sort of fantastic
aggregate or compound of past motions.
As long as we are awake, the fresh, forceful motions coming in from
the senses will tend to engross all of our attention, and we will not notice
these fantastic creations. But
whenever our experiences turn dull, or we are bored, we will notice other
motions, that is, we will fantasize and daydream. It is not that we deliberately cause our
fantasies by actively creating images; it is rather that those confused
motions that happen, for purely mechanical reasons, to be reverberating in
the mind at the time are the ones that we end up attending to and imagining. Hobbes supposed that
over the course of the day our senses, being constantly buffeted by stimuli,
get wounded and shrink back from the outer surfaces of our bodies. When this happens, we start to lose contact
with the incoming sensations. This
just is to become drowsy, and eventually we fall asleep. Then fantastic images, compounded from past
experiences, float into our attention, like stars becoming visible at night
after the much brighter sun sets.
Since these images may be quite distinct, they are not taken to be
memories but are confused with actual sensory experiences. That is, we start to dream. Hobbes appealed to
this account to explain away people’s experiences of ghosts and spirits of
the dead. On his account, as people
fall asleep, their senses gradually pull back. The more forceful objects in our
surroundings still affect them, but fainter images from our imaginations
begin to capture our attention. These
two experiences coexist leading us to have the sensation of the imagined
objects existing in the space we are currently sensing. We end up thinking we are seeing a ghost
when in fact we are half dreaming.
Hobbes drew an amusing moral from his theory: that one ought always to
carefully prepare oneself for bed, and never fall asleep in a chair. The preparation and the placement of our
bodies in a special place is a signal to us not to believe that what we are
going to see next will be real. But if
we get drowsy and fall asleep during the day, we may have difficulties
separating dreaming from reality, since the dream images blend with our
waking surroundings. This is what
leads people to believe (falsely) in the existence of ghosts and other
spirits. They think they have actually
seen ghosts of long dead people or other spiritual apparitions when in fact
they were just dreaming. ESSAY QUESTIONS AND RESEARCH PROJECTS
1. Assess the
adequacy of the arguments that Hobbes used over HN II to prove that the
sensible qualities are unreal. How
might someone who is committed to the external existence of these qualities
respond to Hobbes’ arguments, and how effective would those responses be?
2. At HN I.2,
Hobbes said he would base his work on what people know by experience. At HN II.10 he said that, “whatsoever
accidents or qualities our senses make us think there be in the world, they
are not there, but are seemings and apparitions
only.” He further claimed that “The
things that really are in the world without us, are
those motions by which these seemings are
caused.” But if all our knowledge is
supposed to be based on experience, and whatever our senses make us think
there is in the world is not there, how could Hobbes have claimed to know
anything about what really exists in the world without us, particularly that
what is real are “motions?”
3. Assess the
adequacy of Hobbes’ claim that sensible qualities are merely the way that
motions of the parts of our brains appear to us. Aside from problems of justification
(raised in the previous question) the claim poses the problem of how a motion
could even “appear” as a colour, sound, smell, taste or feeling, and the
problem of where colour, sound, smell, taste and feeling exist if they do not
exist in our bodies. What alternatives
did Hobbes have to making this claim, supposing that he wanted to insist that
sensible qualities do not exist outside of us and that the only effect that a
moving object can have on another object is to move it? Is the existence of sensible qualities an
irresolvable problem for Hobbes, or is there some way to reconcile the
apparent existence of sensible qualities with a mechanistic account of
sensation and sensations and a purely materialist account of the mind?
4. Hobbes’
problems defining memory are not unique.
Undertake a critical survey of attempts to explain the phenomenon of
memory in the early modern period. |
