I should be glad to pursue this Discourse, and shew you the whole Series
of the following Truths, which I have drawn from the former: But because
for this purpose, it were now necessary for me to treat of severall
questions, which are controverted by the learned, with whom I have no
desire to imbroil my self, I beleeve it better for me to abstain from
it; and so in generall onely to discover what they are, that I may leave
the wisest to judge whether it were profitable to inform the publick
more particularly of them. I alwayes remained constant to my resolution,
to suppose no other Principle but that which I now made use of, for the
demonstration of the Existence of God, and of the Soul; and to receive
nothing for true, which did not seem to me more clear and more certain
then the demonstrations of Geometry had formerly done. And yet I dare
say, that I have not onely found out the means to satisfie my self, in a
short time, concerning all the principall difficulties which are usually
treated in Philosophy. But that also _I_ have observed certain Laws
which God hath so established in Nature, and of which he hath imprinted
such notions in our Souls, that when we shall have made sufficient
reflections upon them we cannot doubt but that they are exactly observed
in whatsoever either is, or is done in the World. Then considering the
connexion of these Laws, me thinks, I have discovercd divers Truths,
more usefull and important then whatever _I_ learn'd before, or ever
hop'd to learn.
But because _I_ have endeavoured to lay open the principall of them in a
Treatise, which some considerations hinder me from publishing; _I_ can
no way better make them known, then by relating summarily what it
contains.
I had a designe to comprehend all what I thought _I_ knew, before _I_
would write it, touching the nature of material things. But even as
Painters, not being able equally well to represent upon a _flat_ all the
severall facies of a solid body, chuse the principall of them, which
they place towards the light; and shadowing the others, make them appear
no more then they do to our sight: So, fearing lest _I_ should not bring
into this Discourse all which was in my thoughts, _I_ onely undertook to
set forth at large my conceptions touching the light; and upon that
occasion to add somewhat of the Sun, and of the fix'd Stars, by reason
that it proceeds almost all from thence; of the Heavens, because they
transmit it; of the Planets, of the Comets, and of the Earth, because
they cause it to reflect; and in particular, of all Bodies which are on
the earth, whether for that they are either coloured, or transparent, or
luminous; and last of all, of Man, because he is the Spectator thereof.
As also, in some manner to shadow out all these things, and that _I_
might the more freely speak what _I_ judg'd, without being obliged to
follow, or to refute the opinions which are received amongst the
Learned, _I_ resolved to leave all this world here to their disputes,
and to speak onely of what would happen in a new one, if God now created
some where in those imaginary spaces matter enough to compose it, and
that he diversly and without order agitated the severall parts of this
matter, so as to compose a Chaos of it as confused as the Poets could
feign one: and that afterwards he did nothing but lend his ordinary
concurrence to Nature, and leave her to work according to the Laws he
hath established.
Thus first of all _I_ described this Matter, and endevoured to
represent it such, that me thinks there is nothing in the world more
clear, or more intelligible, except what was beforesaid of God, and of
the Soul. For even _I_ expresly supposed that there was in it none of
those forms and qualities which are disputed in the Schools; nor
generally any thing but that the knowledge thereof was so naturall to
our understandings, that we could not even feigne to be ignorant of it.
Besides, I made known what the Laws of Nature were; and without
grounding my reasons on any other principles, but on the infinite
perfections of God, I did endeavour to demonstrate all those which might
be questioned, and to make them appear to be such, that although God had
created divers worlds, there could have been none where they were not
observed. Afterwards _I_ shewed how the greater part of the Matter of
this _Chaos_ ought, according to those Laws, to dispose and order it
self in a certain manner, which would make it like our Heavens: And how
some of these parts were to compose an Earth, and some Planets and
Commets, some others a Sun and fix'd Starrs. And here enlarging my self
on the subject of Light, _I_ at length explain'd what that light was,
which was to be in the Sun and Stars; and thence how it travers'd in an
instant the immense spaces of the Heavens, and how it reflected it self
from Planets and Commets towards the Earth. _I_ added also divers things
touching the substance, situation, the motions, and all the several
qualities of these heavens and these stars: So that _I_ thought _I_ had
said enough to make known, That there is nothing remarkable in those of
this world, which ought not, or at least could not appear altogether
like to these of that world which _I_ described.
Thence _I_ came to speak particularly of the Earth; how, although I had
expresly supposed, that God had placed no weight in the Matter whereof
it was composed; yet all its parts exactly tended towards its center:
How that there being water and air upon its superficies, the disposition
of the Heavens, and of the Starrs, and chiefly of the Moon, ought to
cause a floud and an ebb, which in all circumstances was like to that
which we observe in our Seas; And besides, a certain course aswel of the
water, as of the air, from East to West, as is also observed between the
Tropicks: How the Mountains, the Seas, the Springs and Rivers might
naturally be form'd therein, and Metals run in the mines, and Plants
grow in the Fields, and generally all bodies be therein engendered which
are call'd mixt or composed.
And amongst other things, because that next the Stars, I know nothing in
the world but Fire, which produceth light, I studied to make all clearly
understood which belongs to its nature; how it's made, how it's fed,
how sometimes it hath heat onely without light, and sometimes onely
light without heat; how it can introduce several colours into several
bodies, and divers other qualities; how it dissolves some, and hardens
others; how it can consume almost all, or convert them into ashes and
smoak: and last of all, how of those ashes, by the only violence of its
action, it forms glass. For this transmutation of ashes into glass,
seeming to me to be as admirable as any other operation in Nature, I
particularly took pleasure to describe it.
Yet would I not inferre from all these things, that this World was
created after the manner I had proposed. For it is more probable that
God made it such as it was to be, from the beginning. But it's certain,
and 'tis an opinion commonly received amongst the Divines, That the
action whereby he now preserveth it, is the same with that by which he
created it. So that, although at the beginning he had given it no other
form but that of a Chaos (provided, that having established the Laws of
Nature, he had afforded his concurrence to it, to work as it used to do)
we may beleeve (without doing wrong to the miracle of the Creation) that
by that alone all things which are purely material might in time have
rendred themselves such as we now see them: and their nature is far
easier to conceive, when by little and little we see them brought forth
so, then when we consider them quite form'd all at once.
From the description of inanimate Bodies and Plants, I pass'd to that of
Animals, and particularly to that of Men. But because I had not yet
knowledge enough to speak of them in the same stile as of the others; to
wit, in demonstrating effects by their causes, and shewing from what
seeds, and in what manner Nature ought to produce them; I contented my
self to suppose, That God form'd the body of a Man altogether like one
of ours; aswel the exteriour figure of its members, as in the interiour
conformity of its organs; without framing it of other matter then of
that which I had described; and without putting in it at the beginning
any reasonable soul, or any other thing to serve therein for a
vegetative or sensitive soul; unless he stirr'd up in his heart one of
those fires without light which I had already discovered; and that I
conceiv'd of no other nature but that which heats hay when its housed
before it be dry, or which causes new Wines to boyl when it works upon
the grape: For examining the functions which might be consequently in
this body, I exactly found all those which may be in us, without our
thinking of them; and to which our soul (that is to say, that distinct
part from our bodies, whose nature (as hath been said before) is onely
to think) consequently doth not contribute, and which are all the same
wherein we may say unreasonable creatures resemble us. Yet could I not
finde any, of those which depending from the thought, are the onely ones
which belong unto us as Men; whereas I found them all afterwards, having
supposed that God created a reasonable soul, and that he joyn'd it to
this body, after a certain manner which I describ'd.
But that you might see how I treated this matter, I shall here present
you with the explication of the motion of the heart, and of the
arteries, which being the first and most general (which is observed in
animals) we may thereby easily judge what we ought to think of all the
rest. And that we may have the less difficulty to understand what I
shall say thereof, I wish those who are not versed in Anatomy, would
take the pains, before they read this, to cause the heart of some great
animal which hath lungs, to be dissected; for in all of them its very
like that of a Man: and that they may have shewn them the two cels or
concavities which are there: First that on the right side, whereto two
large conduits answer, to wit, the _vena cava_, which is the principal
receptacle of bloud, and as the body of a tree, whereof all the other
veins of the body are branches; and the arterious vein, which was so
mis-call'd, because that in effect its an artery, which taking its
_origine_ from the heart, divides it self after being come forth, into
divers branches, which every way spred themselves through the lungs.
Then the other which is on the left side, whereunto in the same manner
two pipes answer, which are as large, or larger then the former; to wit,
the veinous artery, which was also il named, forasmuch as its nothing
else but a vein which comes from the lungs, where its divided into
several branches interlaid with those of the arterious vein, and those
of that pipe which is called the Whistle, by which the breath enters.
And the great artery, which proceeding from the heart, disperseth its
branches thorow all the body. I would also that they would carefully
observe the eleven little skins, which, as so many little doors, open
and shut the four openings which are in these two concavities; to wit,
three at the entry of the _vena cava_, where they are so disposed, that
they can no wayes hinder the bloud which it contains from running into
the right concavity of the heart; and yet altogether hinder it from
coming out. Three at the entry of the arterious vein; which being
disposed quite contrary, permit only the bloud which is in that
concavity to pass to the lungs; but not that which is in the lungs to
return thither. And then two others at the entry of the veinous artery,
which permits the bloud to run to the left concavity of the heart, but
opposeth its return. And three at the entry of the great artery, which
permit it to go from the heart, but hinder its return thither. Neither
need we seek any other reason for the number of these skins, save only
that the opening of the veinous artery, being oval-wise, by reason of
its situation, may be fitly shut with two; whereas the other, being
round, may the better be clos'd with three. Besides, I would have them
consider, that the great artery and the arterious vein are of a
composition much stronger then the veinous artery or the _vena cava_.
And that these two later grow larger before they enter into the heart,
and make (as it were) two purses, call'd the ears of the heart, which
are composed of a flesh like it; and that there is always more heat in
the heart then in any other part of the body. And in fine, that if any
drop of bloud enter into these concavities, this heat is able to make it
presently swell and dilate it self, as generally all liquors do, when
drop by drop we let them fall into a very hot vessel.
For after this I need say no more for to unfold the motion of the
heart, but that when these concavities are not full of bloud,
necessarily there runs some from the _vena cava_ into the right, and
from the veinous artery into the left; for that these two vessels are
always full of it, and that their openings which are towards the heart
cannot then be shut: But that assoon as there is thus but two drops of
bloud entred, one in either of these concavities, these drops, which
cannot but be very big, by reason that their openings whereby they enter
are very large, and the vessels whence they come very full of bloud, are
rarified and dilated because of the heat which they find therein. By
means whereof, causing all the heart to swel, they drive and shut the
five little doors which are at the entry of the two vessels whence they
come, hindering thereby any more bloud to fall down into the heart, and
continuing more and more to rarifie themselves, they drive and open the
six other little doors which are at the entry of the other two vessels
whence they issue, causing by that means all the branches of the
arterious vein, and of the great artery, to swel (as it were) at the
same time with the heart: which presently after fals, as those arteries
also do, by reason that the bloud which is entred therein grows colder,
and their six little doors shut up again, and those five of the _vena
cava_, and of the veinous artery open again, and give way to two other
drops of bloud, which again swell the heart and the arteries in the same
manner as the preceding did. And because the bloud which thus enters
into the heart, passeth thorow those two purses, which are call'd the
ears; thence it comes, that their motion is contrary to the heart's, and
that they fall when that swels.
Lastly, That they who know not the force of Mathematical demonstrations,
and are not accustomed to distinguish true reasons from probable ones,
may not venture to deny this without examining it, I shall advertise
them, that this motion which I have now discovered, as necessarily
follows from the onely disposition of the organs (which may plainly be
seen in the heart,) and from the heat (which we may feel with our
fingers,) and from the nature of the bloud (which we may know by
experience,) as the motions of a clock doth by the force, situation and
figure of its weight and wheels.
But if it be asked, how it comes that the bloud of the veins is not
exhausted, running so continually into the heart; and how that the
arteries are not too full, since all that which passeth thorow the heart
dischargeth it self into them: I need answer nothing thereto but what
hath been already writ by an English Physician, to whom this praise must
be given, to have broken the ice in this place, and to be the first who
taught us, That there are several little passages in the extremity of
the arteries whereby the bloud which they receive from the heart,
enters the little branches of the veins; whence again it sends it self
back towards the heart: so that its course is no other thing but a
perpetuall circulation. Which he very wel proves by the ordinary
experience of Chirurgians, who having bound the arm indifferently hard
above the the place where they open the vein, which causeth the bloud to
issue more abundantly, then if it had not been bound. And the contrary
would happen, were it bound underneath, between the hand and the
incision, or bound very hard above. For its manifest, that the band
indifferently tyed, being able to hinder the bloud which is already in
the arm to return towards the heart by the veins; yet it therefore
hinders not the new from coming always by the arteries, by reason they
are placed under the veins, and that their skin being thicker, are less
easie to be press'd, as also that the bloud which comes from the heart,
seeks more forcibly to passe by them towards the hand, then it doth to
return from thence towards the heart by the veins. And since this bloud
which issues from the arm by the incision made in one of the veins, must
necessarily have some passage under the bond, to wit, towards the
extremities of the arm, whereby it may come thither by the arteries, he
also proves very well what he sayes of the course of the bloud through
certain little skins, which are so disposed in divers places along the
veins, which permit it not to pass from the middle towards the
extremities, but onely to return from the extremities towards the heart.
And besides this, experience shews, That all the bloud which is in the
body may in a very little time run out by one onely artery's being cut,
although it were even bound very neer the heart, and cut betwixt it and
the ligature: So that we could have no reason to imagine that the bloud
which issued thence could come from any other part.
But there are divers other things which witness, that the true cause of
this motion of the bloud is that which I have related. As first, The
difference observed between that which issues out of the veins, and that
which comes out of the arteries, cannot proceed but from its being
rarified and (as it were) distilled by passing thorow the heart: its
more subtil, more lively, and more hot presently after it comes out;
that is to say, being in the arteries, then it is a little before it
enters them, that is to say, in the veins. And if you observe, you will
finde, that this difference appears not well but about the heart; and
not so much in those places which are farther off. Next, the hardnesse
of the skin of which the artery vein and the great artery are composed,
sheweth sufficiently, that the bloud beats against them more forcibly
then against the veins. And why should the left concavity of the heart,
and the great artery be more large and ample then the right concavity,
and the arterious vein; unless it were that the bloud of the veinous
artery, having bin but onely in the lungs since its passage thorow the
heart, is more subtil, and is rarified with more force and ease then the
bloud which immediately comes from the _vena cava_. And what can the
Physicians divine by feeling of the pulse, unlesse they know, that
according as the bloud changeth its nature, it may by the heat of the
heart be rarified to be more or lesse strong, and more or lesse quick
then before. And if we examine how this heat is communicated to the
other members, must we not avow that 'tis by means of the bloud, which
passing the heart, reheats it self there, and thence disperseth it self
thorow the whole body: whence it happens, that if you take away the
bloud from any part, the heat by the same means also is taken a way. And
although the heart were as burning as hot iron, it were not sufficient
to warm the feet and the hands so often as it doth, did it not continue
to furnish them with new bloud.
Besides, from thence we know also that the true use of respiration is to
bring fresh air enough to the lungs, to cause that bloud which comes
from the right concavity of the heart, where it was rarified, and (as it
were) chang'd into vapours, there to thicken, and convert it self into
bloud again, before it fall again into the left, without which it would
not be fit to serve for the nourishment of the fire which is there.
Which is confirm'd, for that its seen, that animals which have no lungs
have but one onely concavity in the heart; and that children, who can
make no use of them when they are in their mothers bellies, have an
opening, by which the bloud of the _vena cava_ runs to the left
concavity of the heart, and a conduit by which it comes from the
arterious vein into the great artery without passing the lungs.
Next, How would the concoction be made in the stomach, unlesse the heart
sent heat by the arteries, and therewithall some of the most fluid parts
of the bloud, which help to dissolve the meat receiv'd therein? and is
not the act which converts the juice of these meats into bloud easie to
be known, if we consider, that it is distill'd by passing and repassing
the heart, perhaps more then one or two hundred times a day? And what
need we ought else to explain the nutrition and the production of divers
humours which are in the body, but to say, that the force wherewith the
bloud in rarifying it self, passeth from the heart towards the
extremities or the arteries, causeth some of its parts to stay amongst
those of the members where they are, and there take the place of some
others, which they drive from thence? And that according to the
situation, or the figure, or the smalnesse of the pores which they
meet, some arrive sooner in one place then others. In the same manner
as we may have seen in severall sieves, which being diversly pierc'd,
serve to sever divers grains one from the other. And briefly, that which
is most remarkable herein, is the generation of the animal spirits,
which are as a most subtil wind, or rather, as a most pure and lively
flame, which continually rising in great abundance from the heart to the
brain, dischargeth it self thence by the nerves into the muscles, and
gives motion to all the members; without imagining any other reason
which might cause these parts of the bloud, which being most mov'd, and
the most penetrating, are the most fit to form these spirits, tend
rather towards the brain, then to any other part. Save onely that the
arteries which carry them thither, are those which come from the heart
in the most direct line of all: And that according to the rules of the
Mechanicks, which are the same with those of Nature, when divers things
together strive to move one way, where there is not room enough for all;
so those parts of bloud which issue from the left concavity of the heart
tend towards the brain, the weaker and less agitated are expell'd by the
stronger, who by that means arrive there alone.
I had particularly enough expounded all these things in a Treatise which
I formerly had design'd to publish: In pursuit whereof, I had therein
shewed what ought to be the fabrick of the nerves and muscles of an
humane body, to cause those animall spirits which were in them, to have
the power to move those members. As we see that heads a while after they
are cut off, yet move of themselves, and bite the ground, although they
are not then animated. What changes ought to be made in the brain to
cause waking, sleeping, and dreaming: how light, sounds, smels, tasts,
heat, and all other qualities of exteriour objects, might imprint
severall _Ideas_ by means of the senses. How hunger and thirst, and the
other interiour passions might also send theirs thither. What ought to
be taken therein for common sense, where these _Ideas_ are received; for
memory which preserves them; and for fancy, which can diversly change
them, and form new ones of them; and by the same means, distributing the
animal spirits into the muscles, make the members of the body move in so
many severall fashions, and as fitly to those objects which present
themselves to its senses; and to the interiour passions which are in
them, as ours may move themselves without the consent of the Wil. Which
wil seem nothing strange to those, who knowing how many _Automatas_ or
moving Machines the industry of men can make, imploying but very few
pieces, in comparison of the great abundance of bones, muscles, nerves,
arteries, veins, and all the other parts which are in the body of every
Animal, will consider this body as a fabrick, which having been made by
the hands of God, is incomparably better ordered, and hath more
admirable motions in it then any of those which can be invented by men.
And herein I particularly insisted, to make it appear, that if there
were such Machines which had organs, and the exteriour figure of an Ape,
or of any other unreasonable creature, we should finde no means of
knowing them not to be altogether of the same nature as those Animals:
whereas, if there were any which resembled our bodies, and imitated our
actions as much as morally it were possible, we should always have two
most certain ways to know, that for all that they were not reall men:
The first of which is, that they could never have the use of speech, nor
of other signes in framing it, as we have, to declare our thoughts to
others: for we may well conceive, that a Machine may be so made, that it
may utter words, and even some proper to the corporal actions, which
may cause some change in its organs; as if we touch it in some part, and
it should ask what we would say; or so as it might cry out that one
hurts it, and the like: but not that they can diversifie them to answer
sensibly to all what shall be spoken in its presence, as the dullest men
may do. And the second is, That although they did divers things aswel,
or perhaps better, then any of us, they must infallibly fail in some
others, whereby we might discover that they act not with knowledge, but
onely by the disposition of their organs: for whereas Reason is an
universal instrument which may serve in all kinde of encounters, these
organs have need of some particular disposition for every particular
action: whence it is, that its morally impossible for one Machine to
have severall organs enough to make it move in all the occurrences of
this life, in the same manner as our Reason makes us move. Now by these
two means we may also know the difference which is between Men and
Beasts: For 'tis a very remarkable thing, that there are no men so dull
and so stupid, without excepting those who are out of their wits, but
are capable to rank severall words together, and of them to compose a
Discourse, by which they make known their thoughts: and that on the
contrary, there is no other creature, how perfect or happily soever
brought forth, which can do the like. The which happens, not because
they want organs; for we know, that Pyes and Parrots can utter words
even as we can, and yet cannot speak like us; that is to say, with
evidence that they think what they say. Whereas Men, being born deaf and
dumb, and deprived of those organs which seem to make others speak, as
much or more then beasts, usually invent of themselves to be understood
by those, who commonly being with them, have the leisure to learn their
expressions. And this not onely witnesseth, that Beasts have lesse
reason than men, but that they have none at all. For we see there needs
not much to learn to speak: and forasmuch as we observe inequality
amongst Beasts of the same kind, aswell as amongst men, and that some
are more easily managed then others; 'tis not to be believed, but that
an Ape or a Parrot which were the most perfect of its kinde, should
therein equall the most stupid child, or at least a child of a
distracted brain, if their souls were not of a nature wholly different
from ours. And we ought not to confound words with naturall motions,
which witness passions, and may be imitated by Machines aswell as by
Animals; nor think (as some of the Ancients) that beasts speak, although
we do not understand their language: for if it were true, since they
have divers organs which relate to ours, they could aswell make
themselves understood by us, as by their like. Its likewise very
remarkable that although there are divers creatures which express more
industry then we in some one of their actions; yet we may well perceive,
that the same shew none at all in many others: So that what they do
better then we, proves not at all that they have reason; for by that
reckoning they would have more then any of us, and would do better in
all other things; but rather, that they have none at all, and that its
Nature onely which works in them according to the disposition of their
organs. As wee see a Clock, which is onely composed of wheels and
springs, can reckon the hours, and measure the times more exactly then
we can with all our prudence.
After this I had described the reasonable Soul, and made it appear, that
it could no way be drawn from the power of the Matter, as other things
whereof I had spoken; but that it ought to have been expresly created:
And how it suffiseth not for it to be lodg'd in our humane body as a
Pilot in his ship, to move its members onely; but also that its
necessary it be joyned and united more strongly therewith to have
thoughts and appetites like ours, and so make a reall man.
I have here dilated my self a little on the subject of the Soul, by
reason 'tis of most importance; for, next the errour of those who deny
God, which I think I have already sufficiently confuted, there is none
which sooner estrangeth feeble minds from the right way of vertue, then
to imagine that the soul of beasts is of the same nature as ours, and
that consequently we have nothing to fear nor hope after this life, no
more then flies or ants. Whereas, when we know how different they are,
we comprehend much better the reasons which prove that ours is of a
nature wholly independing from the body, and consequently that it is not
subject to die with it. And that when we see no other cause which
destroys it, we are naturally thence moved to judge that it's immortall.