Chapter II: Part 2

I Know not whether I ought to entertain you with the first Meditations which I had there, for they are so Metaphysicall and so little common, that perhaps they will not be relished by all men: And yet that you may judge whether the foundations I have laid are firm enough, I find my self in a manner oblig'd to discourse them; I had long since observed that as for manners, it was somtimes necessary to follow those opinions which we know to be very uncertain, as much as if they were indubitable, as is beforesaid: But because that then I desired onely to intend the search of truth, I thought I ought to doe the contrary, and reject as absolutely false all wherein I could imagine the least doubt, to the end I might see if afterwards any thing might remain in my belief, not at all subject to doubt. Thus because our senses sometimes deceive us, I would suppose that there was nothing which was such as they represented it to us. And because there are men who mistake themselves in reasoning, even in the most simple matters of Geometry, and make therein Paralogismes, judging that I was as subject to fail as any other Man, I rejected as false all those reasons, which I had before taken for Demonstrations. And considering, that the same thoughts which we have waking, may also happen to us sleeping, when as not any one of them is true. I resolv'd to faign, that all those things which ever entred into my Minde, were no more true, then the illusions of my dreams. But presently after I observ'd, that whilst I would think that all was false, it must necessarily follow, that I who thought it, must be something. And perceiving that this Truth, _I think_, therefore, _I am_, was so firm and certain, that all the most extravagant suppositions of the Scepticks was not able to shake it, I judg'd that I might receive it without scruple for the first principle of the Philosophy I sought.

Examining carefully afterwards what I was; and seeing that I could suppose that I had no _body_, and that there was no _World_, nor any _place_ where I was: but for all this, I could not feign that I _was not_; and that even contrary thereto, thinking to doubt the truth of other things, it most evidently and certainly followed, That _I was_: whereas, if I had ceas'd to _think_, although all the rest of what-ever I had imagined were true, I had no reason to beleeve that _I had been_. I knew then that I was a substance, whose whole essence or nature is, but to _think_, and who to _be_, hath need of no place, nor depends on any materiall thing. So that this _Me_, to wit, my Soul, by which I am what I am, is wholly distinct from the Body, and more easie to be known then _it_; and although _that_ were not, it would not therefore cease to be what it is.

After this I considered in generall what is requisite in a Proposition to make it true and certain: for since I had found out one which I knew to be so, I thought I ought also to consider wherein that certainty consisted: and having observed, That there is nothing at all in this, _I think_, therefore _I am_, which assures me that I speak the truth, except this, that I see most cleerly, That _to think_, one must have a _being_; I judg'd that I might take for a generall rule, That those things which we conceive cleerly and distinctly, are all true; and that the onely difficulty is punctually to observe what those are which we distinctly conceive.

In pursuance whereof, reflecting on what I doubted, and that consequently my _being_ was not perfect; for I clearly perceived, that it was a greater perfection to know, then to doubt, I advised in my self to seek from whence I had learnt to think on something which was more perfect then I; and I knew evidently that it must be of some nature which was indeed more perfect. As for what concerns the thoughts I had of divers other things without my self, as of heaven, earth, light, heat, and a thousand more, I was not so much troubled to know whence they came, for that I observed nothing in them which seemed to render them superiour to me; I might beleeve, that if they were true, they were dependancies from my nature, as far forth as it had any perfection; and if they were not, I made no accompt of them; that is to say, That they were in me, because I had something deficient. But it could not be the same with the _Idea_ of a being more perfect then mine: For to esteem of it as of nothing, was a thing manifestly impossible. And because there is no lesse repugnancy that the more perfect should succeed from and depend upon the less perfect, then for something to proceed from nothing, I could no more hold it from my self: So as it followed, that it must have bin put into me by a Nature which was truly more perfect then _I_, and even which had in it all the perfections whereof I could have an _Idea_; to wit, (to explain my self in one word) God. Whereto I added, that since I knew some perfections which I had not, I was not the onely _Being_ which had an existence, (I shall, under favour, use here freely the terms of the Schools) but that of necessity there must be some other more perfect whereon I depended, and from whom I had gotten all what I had: For had I been alone, and depending upon no other thing, so that I had had of my self all that little which I participated of a perfect Being, I might have had by the same reason from my self, all the remainder which I knew I wanted, and so have been my self infinite, eternall, immutable, all-knowing, almighty; and lastly, have had all those perfections which I have observed to be in God. For according to the way of reasoning I have now followed, to know the nature of God, as far as mine own was capable of it, I was onely to consider of those things of which I found an _Idea_ in me, whether the possessing of them were a perfection or no; and I was sure, that any of those which had any imperfections were not in him, but that all others were. I saw that doubtfulness, inconstancy, sorrow and the like, could not be in him, seeing I could my self have wish'd to have been exempted from them. Besides this, I had the _Ideas_ of divers sensible and corporeall things; for although I supposed that I doted, and that all that I saw or imagined was false; yet could I not deny but that these _Ideas_ were truly in my thoughts. But because I had most evidently known in my self, That the understanding Nature is distinct from the corporeall, considering that all composition witnesseth a dependency, and that dependency is manifestly a defect, I thence judged that it could not be a perfection in God to be composed of those two Natures; and that by consequence he was not so composed. But that if there were any Bodies in the world, or els any intelligences, or other Natures which were not wholly perfect, their being must depend from his power in such a manner, that they could not subsist one moment without him.

Thence I went in search of other Truths; and having proposed _Geometry_ for my object, which I conceived as a continued Body, or a space indefinitely spred in length, bredth, height or depth, divisible into divers parts, which might take severall figures and bignesses, and be moved and transposed every way. For the Geometricians suppose all this in their object. I past through some of their most simple demonstrations; and having observed that this great certaintie, which all the world grants them, is founded only on this, that men evidently conceived them, following the rule I already mentioned. I observed also that there was nothing at all in them which ascertain'd me of the existence of their object. As for example, I well perceive, that supposing a Triangle, three angles necessarily must be equall to two right ones: but yet nevertheless I saw nothing which assured me that there was a Triangle in the world. Whereas returning to examine the _Idea_ which I had of a perfect Being, _I_ found its existence comprised in it, in the same manner as it was comprised in that of a Triangle, where the three angles are equall to two right ones; or in that of a sphere, where all the parts are equally distant from the center. Or even yet more evidently, and that by consequence, it is at least as certain that God, who is that perfect Being, is, or exists, as any demonstration in Geometry can be.

But that which makes many perswade themselves that there is difficulty in knowing it, as also to know what their Soul is, 'tis that they never raise their thoughts beyond sensible things, and that they are so accustomed to consider nothing but by imagination, which is a particular manner of thinking on materiall things, that whatsoever is not imaginable seems to them not intelligible. Which is manifest enough from this, that even the Philosophers hold for a Maxime in the Schools, That there is nothing in the understanding which was not first in the sense; where notwithstanding its certain, that the _Ideas_ of God and of the Soul never were. And (me thinks) those who use their imagination to comprehend them, are just as those, who to hear sounds, or smell odours, would make use of their eys; save that there is yet this difference, That the sense of seeing assures us no lesse of the truth of its objects, then those of smelling or hearing do: whereas neither our imagination, nor our senses, can ever assure us of any thing, if our understanding intervenes not.

To be short, if there remain any who are not enough perswaded of the existence of God, and of their soul, from the reasons I have produc'd, I would have them know, that all other things, whereof perhaps they think themselves more assured, as to have a body, and that there are Stars, and an earth, and the like, are less certain. For although we had such a morall assurance of these things, that without being extravagant we could not doubt of them. However, unless we be unreasonable when a metaphysicall certainty is in question, we cannot deny but we have cause enough not to be wholly confirmed in them, when we consider that in the same manner we may imagine being asleep, we have other bodies, and that we see other Stars, and another earth, though there be no such thing. For how doe we know that those thoughts which we have in our dreams, are rather false then the others, seeing often they are no less lively and significant, and let the ablest men study it as long as they please, I beleeve they can give no sufficient reason to remove this doubt, unless they presuppose the existence of God. For first of all, that which I even now took for a rule, to wit, that those things which were most clearly and distinctly conceived, are all true, is certain, only by reason, that God is or exists, and that he is a perfect being, and that all which we have comes from him. Whence it follows, that our Idea's or notions, being reall things, and which come from God in all wherein they are clear and distinct, cannot therein be but true. So that if we have very often any which contain falshood, they cannot be but of such things which are somewhat confus'd and obscure, because that therein they signifie nothing to us, that's to say, that they are thus confus'd in us only, because we are not wholly perfect. And it's evident that there is no less contrariety that falshood and imperfection should proceed from God, as such, then there is in this, that truth and falshood proceed from nothing. But if we know not that whatsoever was true and reall in us comes from a perfect and infinite being, how clear and distinct soever our Idea's were, we should have no reason to assure us, that they had the perfection to be true.

Now after that the knowledge of God, and of the Soul hath rendred us thus certain of this rule, it's easie to know; that the extravaganceys which we imagin in our sleep, ought no way to make us doubt of the truth of those thoughts which we have being awake: For if it should happen, that even sleeping we should have a very distinct Idea; as for example, A Geometritian should invent some new demonstration, his sleeping would not hinder it to be true. And for the most ordinary error of our dreames, which consists in that they represent unto us severall objects in the same manner as our exterior senses doe, it matters not though it give us occasion to mistrust the truth of those Ideas, because that they may also often enough cozen us when we doe not sleep; As when to those who have the Jaundies, all they see seems yellow; or, as the Stars or other bodies at a distance, appear much less then they are. For in fine, whether we sleep or wake, we ought never to suffer our selves to be perswaded but by the evidence of our Reason; I say, (which is observable) Of our Reason, and not of our imagination, or of our senses. As although we see the Sun most clearly, we are not therefore to judge him to be of the bigness we see him of; and we may well distinctly imagine the head of a Lion, set on the body of a Goat, but therefore we ought not to conclude that there is a _Chimera_ in the world. For reason doth not dictate to us, that what we see or imagine so, is true: But it dictates, that all our Idea's or notions ought to have some grounds of truth; For it were not possible, that God who is all perfect, and all truth, should have put them in us without that: And because that our reasonings are never so evident, nor so entire while we sleep, as when we wake, although sometimes our imaginations be then as much or more lively and express. It also dictates to us, that our thoughts, seeing they cannot be all true by reason that we are not wholly perfect; what they have of truth, ought infallibly to occur in those which we have being awake, rather then in our dreams.

Part. V.

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.

PART. VI.

Its now three years since I ended the Treatise which contains all these things, and that I began to review it, to send it afterwards to the Presse, when I understood, that persons to whom I submit, and whose authority can no lesse command my actions, then my own Reason doth my thoughts, had disapproved an opinion in Physicks, published a little before by another; of which I will not say that I was, but that indeed I had observed nothing therein, before their censure, which I could have imagined prejudiciall either to Religion or the State; or consequently, which might have hindred me from writing the same, had my Reason perswaded mee thereto. And this made me fear, lest in the same manner there might be found some one amongst mine, in which I might have been mistaken; notwithstanding the great care I always had to admit no new ones into my belief, of which I had not most certain demonstrations; and not to write such as might turn to the disadvantage of any body. Which was sufficient to oblige me to change my resolution of publishing them. For although the reasons for which I had first of all taken it, were very strong; yet my inclination, which alwayes made me hate the trade of Book-making, presently found me out others enough to excuse my self from it. And these reasons on the one and other side are such, that I am not only somewhat concern'd to speak them; but happily the Publick also to know them.

I never did much esteem those things which proceeded from mine own brain; and so long as I have gathered no other fruits from the Method I use, but onely that I have satisfied my self in some difficulties which belong to speculative Sciences, or at least endeavoured to regulate my Manners by the reasons it taught me, I thought my self not obliged to write any thing of them. For, as for what concerns Manners, every one abounds so much in his own sense, That we may finde as many Reformers as heads, were it permitted to others, besides those whom God hath established as Soveraigns over his people, or at least, to whom he hath dispensed grace and zeal enough to be Prophets, to undertake the change of any thing therein. And although my Speculations did very much please me, I did beleeve that other men also had some, which perhaps pleas'd them more. But as soon as I had acquired some generall notions touching naturall Philosophy, and beginning to prove them in divers particular difficulties, I observed how far they might lead a man, and how far different they were from the principles which to this day are in use; I judg'd, that I could not keep them hid without highly sinning against the Law, which obligeth us to procure, as much as in us lies, the general good of all men. For they made it appear to me, that it was possible to attain to points of knowledge, which may be very profitable for this life: and that in stead of this speculative Philosophy which is taught in the Schools, we might finde out a practicall one, by which knowing the force and workings of Fire, Water, Air, of the Starrs, of the Heavens, and of all other Bodies which environ us, distinctly, as we know the several trades of our Handicrafts, we might in the same manner employ them to all uses to which they are fit, and so become masters and possessours of Nature. Which is not onely to be desired for the invention of very many expedients of Arts, which without trouble might make us enjoy the fruits of the earth, and all the conveniences which are to be found therein: But chiefly also for the preservation of health, which (without doubt) is the first good, and the foundation of all other good things in this life. For even the minde depends so much on the temper and disposition of the organs of the body, that if it be possible to finde any way of making men in the generall wiser, and more able then formerly they were, I beleeve it ought to be sought in Physick. True it is, that which is now in use contains but few things, whose benefit is very remarkable: But (without any designe of slighting of it) I assure my self, there is none, even of their own profession, but will consent, that whatsoever is known therein, is almost nothing in companion of what remains to be known. And that we might be freed from very many diseases, aswell of the body as of the mind, and even also perhaps from the weaknesses of old age, had we but knowledge enough of their Causes, and of all the Remedies wherewith Nature hath furnished us. Now having a designe to employ all my life in the enquiry of so necessary a Science; and having found a way, the following of which me thinks might infallibly lead us to it, unless we be hindred by the shortness of life, or by defect of experiments. I judg'd that there was no better Remedie against those two impediments, but faithfully to communicate to the publique, all that little I should discover, and to invite all good Wits to endevour to advance farther in contributing every one, according to his inclination and power, to those Experiments which are to be made, and communicating also to the publique all the things they should learn; so that the last, beginning where the precedent ended, and so joyning the lives and labors of many in one, we might all together advance further then any particular Man could do.