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LECTURE VI.
Of the Five Senses of Man, and of his Understanding
AT our next meeting there was a great
deal of good company, who came to
hear the Boys Philosophy, as they called it;
on which account I could observe that Master Telescope took less pains to be understood by
the young Gentlemen and Ladies, and ad
dressed himself more particularly to those of
greater abilities.
As the company came in laughing, and af
fected to talk, and behaved in a supercilious
manner, which even some great personages
do in these our days of refinement, he stood
silent, till my Lord Marquis desired him to
open the Lecture; upon which he bowed,
to his Lordship and the rest of the company
and began; but had scarcely spoke three
words before he was interrupted by Sir Harry; he therefore stopt for some time,
and then began again; but the tongue of
the young Baronet soon silenced him, and he
stood, without speaking, a considerable time.
On this the company looked at each other,
says the Marchioness, how can you expect
this young Gentleman to read a long Lec
ture, when you know that Sir Harry, who
loves to hear himself talk of all things, has
not patience to support so much taciturnity!
Why, Madam, says the Ambassador of Bantam (who came in with the Marquis) I
After the cursory view of Nature, which
was concluded in my last Lecture, it may
not be amiss to examine our own faculties,
and see by what means we acquire and trea
sure up a knowledge of these things; and
this is done, I apprehend, by means of
the senses, the operations of the mind, and the memory, which last may be called the Store
house of the understanding. The first time
little Master is brought to a looking-glass,
he thinks he has found a new play-mate, and
calls out Little boy! little boy! for having
never seen his own face before, it is no won
der that he should not know it. Here is the
idea, therefore, of something new acquired
by sight.--Presently the father, and mother,
and nurse come forward to partake of the
in the glass with whom he is so well acquaint
ed, he immediately calls out, There, Papa! there, Mamma! there. Nurse! And now the
The whole company were pleased with
this familiar demonstration; but Sir Harry
asked how he came, of all things, to make
use of a looking-glass? Because, Sir, says
he, it is an object with which some people
are the most intimately acquainted.--As Sir Harry is an egregious fop, this reply pro
duced a loud laugh, and Master Telescope
was looked upon to be a Wit as well as a Philosopher; however, I am inclined to
think the expression was accidental, and not
intended to hit Sir Harry, because I know
his good sense would not permit him to treat
an elder and superior in that manner.--The
laugh being a little subsided, our Philosopher
thus proceeded on his Lecture.
All our ideas, therefore, are obtained ei
ther by sensation or reflection, that is to say, seeing, hearing, smelling, tasting, and
Before you proceed further, says the Coun
tess of Twylight, you should, I think, ex
plain to the company what is meant by the
term idea. That, I apprehend, is suffi
ciently explained by what was said about the
looking-glass, says the Philosopher; but if
your Ladyship requires another definition
you shall have it. By an idea, then, I
mean that image or picture, Madam, which
is formed in the mind, of any thing which we
have seen, or even heard talk of; for the
mind is so adroit and ready at this kind of painting, that a town, for instance, is no
sooner mentioned, but the imagination shapes
it into form and presents it to the memory.
None of this company, I presume, have ever
seen Dresden, yet there is not one, perhaps,
but has formed, or conceived in his mind,
some idea or picture of that unhappy place.
Not one of us ever saw N abob's prodi
I shall begin my discourse of the Senses
with that of the Sight, says he, because,
as Mr. Addison observes, the sight is the
most perfect and pleasing of them all.
The organ of seeing is the eye, which is
made up of a number of parts, and so won
derfully contrived for admitting and refract
ing the rays of light, that those which come
from the same point of the object, and fall
upon different parts of the pupil, are again
brought together at the bottom of the eye,
and by that means the whole object is retina,
which is spread there.
But how is it possible, says Sir Harry, for
you to know that the object is thus painted
on the retina? In some measure from the
structure of the eye, replied the Philosopher;
but, I think, it is manifest from that disor
der of the eye which Surgeons call the gutta serena, the very complaint which my Lord's
That which produces in us the sensation
which we call Seeing, is light, for without light nothing is visible. Now light may be
considered either as it radiates from luminous
bodies directly to our eyes, and thus we see
those luminous bodies themselves; as the Sun, a lighted torch, &c. or as it is reflected
from other bodies, and thus we see a flower,
a man, &c. or a picture reflected from them
to our eyes by the rays of light.
It is to be observed that the bodies which
respect the light are of three sorts, 1. Those
fix'd stars. 2. Those that transmit the rays
of light, as the air; and, 3. Those that re
flect them, as the Moon, the Earth, Iron,&c.
. The first we call luminous, the second pellucid, and the third,
If the eye be placed directly in the Me
dium through which the rays pass to it, the
Medium is not seen; for we never see the
air through which the rays come to our eyes.
But if a pellucid body, thro' which the rays are
to pass, be placed at a distance from our eye,
that body will be seen, as well as those bo
dies from whence the rays came that pass
through it to our eyes: for instance, he who
looks through a pair of spectacles, not only
sees bodies through them, but also sees the
glas
body, reflects some rays of light from its
surface; and being placed at a convenient
reflected rays, at the same time that bodies,
at a greater distance, are seen by the trans
mitted rays; and this is the reason, perhaps,
why objects are seen more distinctly through
a reflecting, than through a refracting tele
scope.
There are two kinds of opaque bodies,
namely, those that are not specular, as the moon, the earth, a horse, a man, &c. and
others that are specular or mirrors, like those
in reflecting telescopes, whose surfaces being
polished, reflect the rays in the same order
as they came from other bodies, and shew
us their images. And rays that are thus re
flected from opaque bodies, always bring with
them to the eye the idea of colour, tho' this
colour in bodies is nothing more than a dis
position to reflect to the eye one sort of rays
more copiously or in greater plenty than an
other; for particular rays impress upon the
eye particular colours; some are red, others blue, yellow, green, &c. Now it is to be
observed, that every, body of light which
comes from the Sun seems to be compounded
of those various sorts of rays; and as some of
them are more refrangible than others, that
is to say, are more turned out of their course
in passing from one medium to another, it
rated after such refraction, and their colours
appear distinct. The most refrangible of
these are the violet, and the least the red;
the intermediate ones, in order, are indigo, blue, green, yellow, and
How do you know, Mr. Philosopher,
that colours are separated in this manner?
says Sir Harry. I have no notion of these
doctrines without demonstration. That you
may have, if you please, replied the Philo
sopher. Pray, Master Lovelace, hand me
that Prism.
Now, Sir Harry, if you will please to
hold this prism in the beams of the Sun, you
will see the colours separated in the manner
I have mentioned. Please to look, Lady Caroline, the separation is very pleasing, and
you will find what I said of the rainbow in
ment.
All these rays differ not only in refrangibility, but in
The whiteness of the Sun's light is owing,
it is supposed, to a mixture of all the orig
inal colours in a due proportion; and whiteness in other bodies, is a disposition to reflect
Light, as we have already observed, is
successively propagated with most amazing
swiftness; for it comes from the Sun to the
Earth in about seven or eight minutes, tho'
at the distance of seventy millions of miles.
Hearing is the next most extensive of our Ear, whose
structure is extremely curious, as may be seen
in the books of Anatomy.
That which the ear conveys to the
brain is called sound, tho' till it reaches
and affects the perceptive part, it is in rea
lity nothing but motion; and this mo
tion, which produces in us the perception of
sound, is a vibration of the air, occasioned
by a very short and quick tremulous motion
of the body from whence it is propagated.
That sound is conveyed in this manner, may
be known by what is observed and felt in
the strings of musical instruments, and of
bells, which tremble or vibrate as long as
we perceive any sound come from them;
and from this effect which they produce in
us they are called Sounding Bodies.
Sound is propagated at a great rate, but
not near so fast as light. I don't know that,
says Lady Caroline. Then your Ladyship
has forgotten what passed in our Lecture upon Air, replied the Philosopher; and to confirm
by experiment what I advanced, I must beg
his Lordship to order one of the servants to
go to a distance into the park, and discharge a gun. The Gentlemen were averse to this,
it being an observation they had made an
people, my Lord ordered his Game-keeper
out, and when the piece was discharged,
they had the satisfaction of seeing the fire
long before they heard the report.
Smelling is another sense which seems
to be excited in us by external bodies, and
sometimes by bodies at a great distance; but
that which immediately affects the nose, the
organ of smelling, and produces in us the
sensation of any smell, are effluvia or invisi
ble particles that fly from those bodies to our olfactory nerves. How do you prove this,
young Gentleman? says Sir Harry. Sir, re
plied the Philosopher, had you been here ye
sterday, you would not have asked this que
stion, for, as the wind was North-East, the effluvia from my Lord's brick-kilns were
ready to suffocate us; but now the wind is
turned to the South-West you observe no
such thing, because those effluvia are driven
a contrary way.
The power which some bodies have of
emitting these effluvia or steams without be
ing visibly diminished, is to me most amaz
ing; yet that it is true we know by abundant
experience. A single grain of musk will scent
a thousand rooms, and send forth these odo
riferous particles for a great number of years
must be extremely small; yet their minute
ness is nothing when compared with the par
ticles of light, which pervade and find their
way thro' glass, or to the magnetic effluvia
which pass freely through metallic bodies;
whereas those effluvia that produce the sen
sation of smelling, notwithstanding their
wonderful property of scenting all places into
which they are brought, and without any
sensible diminution, are yet too gross to pass
the membranes of a bladder, and many of
them will scarce find their way through
common white paper.
There are but few names to express the
infinite number of scents that we meet with.
I know of none but those of sweet, stinking, rank, musty, and
The next sense under our consideration is Taste, the organ of which is the tongue
and the palate, but principally the tongue.
Ay, and a pretty organ it is, says Lady Caroline.roline. When used with your Ladyship's dis
cretion, Madam, replied the Philosopher.
But I must observe to your Ladyship, and
the rest of the good company, that though
bodies which emit light, sounds, and scents,
are seen, heard, and smelt at a distance; yet
no bodies can produce taste, without being
immediately applied to the organ; for tho'
the meat be placed at your mouth, you know
not what taste it will produce till you have
touched it with your tongue or palate.
Though there are an amazing variety of
tastes, yet here, as in scents, we have but a few
general names to express the whole; sweet, sour, bitter, harsh, smooth, and
When the Ambassador had sat down with
a sigh, and Lady Caroline had wiped the
precious pearly drops from her cheeks, our
Philosopher arose and thus pursued his Lec
ture.
I have already taken notice of four of our
senses, and am now come to the fifth and
last, I mean that of the Touch, which is
a sense spread over the whole body, tho' it
is more particularly the business of the hands
and fingers; for by them the tangible quali
ties of bodies are known, since we discover
by the touch of the fingers, and sometimes,
indeed, by the touch of other parts of the
body, whether things are hard, soft, rough, smooth, wet, dry, &c. But the qualities which
What we call heat is occasioned by the
agitation of the insensible parts of the body
that produces in us that sensation; and when
the parts of a body are violently agitated,
we say, and indeed we feel, that body is hot, so that that which to our sensation is heat, in the object is nothing but motion.
Hey-day, says Lady Caroline, what sort of
Philosophy is this? Why, Madam, says Sir Harry, this is a position which has been laid
down by these airy Gentlemen for a long
time, but which never has been proved by
experiment. Take care, Baronet, says the
Marquis, or you'll forfeit all pretensions to
Philosophy. The forfeiture, my Lord, is
made already, says the Philosopher; Sir Harry has been bold enough to deny that
which experience every day confirms for
truth. If what we call Heat is not motion,
or occasioned by the motion of bodies, how
came my Lord's mill to take fire the other
day, when it was running round without a
proper supply of corn? And how came your
post-chariot to fire while running down Breakneck hill, Sir Harry? Consider, there
was nobody with a torch under the axle-
even to the poor ignorant Indians, who,
when hunting at a great distance from home,
and wanting fire to dress their meat, take
a bow and a string and rub two pieces of
wood together till they produce flame. But
you may see, Sir Harry, that heat is occa
sioned by the motion of bodies, by only rub
bing this piece of smooth brass on the table
--stay, I'll rub it. — It must be done briskly.
There, now you'll feel it hot; but cease
this motion for a time, and the brass will
become cold again; whence we may infer,
that as heat is nothing but the insensible parti
cles of bodies put into motion, so cold,
on the contrary, is occasioned by the cessa
tion of the motion of those particles, or their
being placed in a state of rest.
But bodies appear hot or cold in proportion
to the temperament of that part of the hu
man body to which they are applied; so
that what seems hot to one, may not seem so
to another: This is so true, that the same
body felt by the two hands of the same man,
may at the same instant of time appear warm
to the one hand, and cold to the other, if
with the one hand he has been rubbing any
thing, while the other was kept in a state of
rest; and for no other reason but because
hand with which he has been rubbing, will
be more brisk than the particles of the other
which was at rest.
I have mentioned those objects which are
peculiar to each of our senses, as light and colour to the sight; sound to the hearing; odors to the smell, &c. but there are two
others common to all the senses, which de
serve our notice, and these are pleasure and pain, which the senses may receive by their
own peculiar objects; for we know that a
proper portion of light is pleasing, but that
too much offends the eye; some sounds de
light, while others are disagreeable, and
grate the ear; so heat, in a moderate de
gree, is very pleasant; yet that heat may be
so increased as to give the most intolerable
pain. But these things are too well known
to be longer insisted on.
Now from the ideas or conceptions formed
in the mind, by means of our senses, and the
operations of the mind itself, are laid the
foundation of the human understanding, the
lowest degree of which is perception; and to
conceive a right notion of this, we must dis
tinguish the first objects of it, which are simple ideas, such as are represented by the
words, red, blue, bitter, sweet, &c. from the
may add the internal operations of our own
minds, or the objects of reflection, such as
are thinking, willing, &c. for all our ideas
are first obtained by sensation and refle ction.
The next operation of the mind (or of the
understanding) in its progress to knowledge, is
that of abstracting its ideas; for by abstraction
they are made general; and a general idea
is to be considered as separated from time and
place, and lodged in the mind to represent
any particular thing that is conformable to it.
Knowledge, which is the highest degree
of the speculative faculties, consists in the
perception of the truth of affirmative or ne
gative propositions; and this perception is
either immediate or mediate. When, by
comparing two ideas together in the mind,
we perceive their agreement or disagreement,
as that black is not white; that the whole is
bigger than a part; that two and two are
equal to four, &c. it is called immediate per
ception, or intuitive knowledge; and as the
truth of these and the like propositions is
tion of the ideas themselves, they are also
called self-evident propositions.
Mediate perception, is when the agreement
or disagreement of two ideas is made known
by the intervention of some other ideas:
Thus if it be affirmed that my Lord's bay
horse is as high as my father's, the agree
ment or disagreement may be seen by apply
ing the measure to both; and this is
called demonstration, or rational knowledge.
The dimensions of any two bodies which
cannot be brought together, may be thus
known, by the same measure being applied
to them both.
But the understanding is not confined to
certain truth; it also judges of probability,
which consists in the likely agreement or dis
agreement of ideas; and the assenting to any
proposition as probable, is called opinion, or belief. — We have now finished this Course of
Lectures. I hope not, says Lady Caroline,
with some emotion! — Why, Madam, return
ed the Philosopher, we have taken a cursory
view of natural bodies, and their causes and
effects; which I have endeavoured to explain
in such a manner as to be intelligible, at
least, if not entertaining; and pray what
more did your Ladyship expect? Sir, replied
count you have given us, and I thank you,
Sir, for the pains you have taken to answer
the many questions I have troubled you
with. What I had farther to hope, was,
that you would have given us, when you
was on the subject of Animals, some
strictures on the cruelty with which they
are too often treated; and have thrown in
reflections and observations tending to in
force in mankind a different conduct.
This I wished for, and should have been
glad to have had Sir Thomas and his Lady
here at the same time; who are both ex
tremely fond of their little domestic crea
tures, and I admire them for their tender
ness and compassion. These feelings and
sentiments of the human heart, Madam, says
the Philosopher, add much to the dignity of
our nature, and I am greatly delighted with
such behaviour; but I am afraid, Lady Caroline, that we often mistake characters of
Benevolence, Lady Caroline, should be
universal, for it is an emanation of the Su
preme Being, whose mercy and goodness are
extended to all his creatures; as ours also
should be, for they are fellow tenants with us
of the globe we inhabit.
I have often thought, Madam, that most
of the mischiefs which embarrass society, and
render one man contemptible to another,
are owing to inordinate ambition or extreme
love of power, and of wealth, the means
by which it is procured; for all the gold a
man possesses beyond that portion which is
to inflame his ambition; as all the wine we
drink more than is necessary to recruit the
drooping spirits, answers no other purpose
but to intoxicate the mind.
I have seen a book, Lady Caroline, in
my Pappa's library, which gives some ac
count of one Lycurgus, an old Grecian Law
giver, with whose character you ought to be
acquainted. — This man, Madam, was of
opinion, that religion, virtue, and good
manners, were the only natural cements and
preservatives of liberty, peace, and friendship;
which he found had been destroyed and ex
tirpated by means of wealth and self-interest;
he therefore prohibited the use of gold and
silver, and all kinds of luxury in the state,
and established such a plan for the education
of youth of every denomination, as was most
likely to confirm and habituate them in the
practice of religion and virtue, and secure to
the Spartans and their posterity the blessings
of liberty and peace.
The event proved that his institutions
were founded on sound policy, and a perfect
knowledge of human nature; for in the
space of five hundred years, that is to say,
from the time of Lycurgus to the introduction
of wealth into the state by Lysander, in the reign Agis, there was no mutiny among
the people; every man submitted chear
fully to the laws of Lycurgus, and all were so
united and powerful in consequence of their
virtue, sobriety, and the martial discipline he
had established (which was that of a national
militia) that Sparta, a very small and inconsidera
ble State, not only gave laws to the rest of Greece, but made even the Persian Monarchs
tremble, though masters of the richest and
most extensive empire in the world. But
when these great and virtuous people of Sparta had conquered Athens, and from
thence introduced wealth and luxury into
their own country, they lost their virtue,
dwindled to nothing, and were themselves
enslaved. Nor is this a matter of wonder;
for where Religion and Virtue are set at a
distance, and Wealth leads the way to posts
of honour and trust, some people will stick
at nothing to obtain gold; but were dignities
of this kind conferred on the most deserving,
and none but men of virtue and superior abi
lities promoted to places of trust and power,
there would be no frauds in the State, or vi
olence among the People, and we might
then hope to enjoy the felicities of the Golden Age.
F I N I S.