The Human Body is a Sort of Machine (1680-82)

LH III 1, 2. For the original Latin text, please go here.  To view the original manuscript, please go here.)

THE DESCRIPTION OF A MACHINE IS BEST APPROACHED THROUGH ITS FINAL CAUSE.

The human body, like the body of any animal, is a sort of machine.  Any machine moreover is best defined in terms of its final cause, so that in the description of the parts it is therefore apparent in what way  each of them is coordinated with the others for the intended use. Thus one who is to describe a given clock will say that it is a Machine made to display equal divisions of time, and therefore the function of a clock-hand lies in its uniform motion for some period of time; and, further, he will say that for this motion a motive force is required, which arises from weight or from elastrum;  further, he will say that an impediment is required in order that the force should not be exercised suddenly (which may arise equally in the wheels as in the obstacle that moves back and forth); to such an extent, finally, he will say that a rule of uniformity is required, which is obtained in the first place from the elastic coil, or from the oscillations of some body, either heavy or elastic, or even from a certain period we have described elsewhere. 

THE AIM OF NATURE IN THE ANIMALS IT PRODUCES CAN BE CONSIDERED TO BE THAT OF CONSERVING, AS MUCH AS POSSIBLE, AND WITH RESPECT TO ITS PARTICULAR SPECIES, A MACHINE OF PERPETUAL MOTION IN THE UNIVERSE

Though it be difficult moreover to determine the ends of things and the purpose of nature before the event, after something has been carried through to the end it is possible to determine what nature wished to do from what it did do.  Wherefore if we wish to bring together into one whole everything that nature aimed at insofar as is permitted to the admirable artifice of Animals, and to establish a sufficiently simple concept, which contains all the rest by means of consequences, we should say: the Bodies of Animals are Machines of perpetual motion, or, to put it more clearly, they are machines comparable to a certain fixed and singular species of perpetual organic motion that is always maintained in the world.  Thus for as long as there are spiders there will be weaving machines, for as long as there are bees there will be honey-producing machines, and for as long as there are squirrels there will be dancing machines.   Thus the aim of nature when it produces an animal is a perpetual-motion machine, as against the aim of the mechanists, who are seeking after perpetual motion by a useless labor, in order to obtain something like an animal that it is not necessary to feed.  On the other hand, this our definition of the animal may appear to resemble an enigma.  Indeed, if it be asked, what is a machine of perpetual motion?, not everyone will at once guess that the Animal is what is had in mind.  It is nevertheless not for this reason to be rejected; often indeed this very thing happens in these definitions --which are not nominal but real or causal-- whenever they are, evidently, sought from causes not immediately forthcoming.  It is thus apparent in what way, moreover, from this singular notion the entire composition of the animal follows straightaway (it is on the other hand granted that plants conserve their species while nevertheless lacking any notable motion, and machines do not have a species).

FOR THIS PERPETUAL MOTION IT IS NECESSARY THAT THE ANIMAL CONSERVE ITS FORCES; THAT IT BE BROUGHT TO THOSE THINGS THAT ARE FITTING TO THIS END, AND THAT IT AVOID THEIR CONTRARIES; THAT IT BE SO CONSTITUTED AS TO JUDGE OF THE DIFFERENCE; AND FINALLY THAT IT BE ABLE TO PROPAGATE ITS SPECIES

In any Machine not only is a proper structuring of the parts needed, but also a motive force.  And as the parts do not so much come into contact with external ones, but rather with one another reciprocally --which is called ‘friction’-- a certain durability is required of them, which is obtained now through their firmness, now indeed through their frequent renewal.  Neither indeed, since the motive force be always finite, is a purely Mechanical perpetual motion possible, hence for the continuation of the machine an external restitution of the power of motion is needed.  Further, in order that men should obtain this durability of action in their machines, they now add to them a quasi-perpetual machine that is made by nature, which is of course man himself, the pilot, who repairs what is weakened or broken down in time, who applies an external force, bringing agents together with patients, or indeed attracts the weight or Elastrum itself, or in some other way conserves the power of the Machine.  Nature moreover brings it about that her Machine is able to do this very thing on its own, that is, that it be able now to be nourished, whereby worn-down parts and forces are renewed, now to be itself moved towards the nutriments that are to be obtained and towards other means of sustaining its functions, as well as [away from] impediments that are to be avoided; now, finally, that it be warned by internal and external things, and that it be prompted toward the fitting motion.  As, to be sure, many external things may arise, all of which it is impossible for such a Machine to avoid without the singular care of a superior providence, for that reason in order that nature look after eternity --and since it is not able easily to conserve the individual, at least it conserves the species of the Machine and of its mechanical motion to the extent possible-- it contrives a way in which Machines are able to produce others of a nature similar to themselves; and therefore through nature’s end, we have at once the origin of three functions, to wit, vital, animal, and genital.   

THE FIRST MOVER IN THIS MACHINE IS SOMETHING ANALOGOUS TO A FLAME OR TO THE SUN OR A FIXED STAR, FROM WHICH THERE ARISES AN EBULLITION WHICH FEEDS ITSELF

With a view to what is to be taught, we now imagine the thing to be within our power, and that it is up to us to construct, by the art of Prometheus, an animal machine, we will indeed easily observe, the function of the first mover in the machine is entrusted to nothing explored by us more suitably than [to] what is similar to a flame, in which once it is kindled, for as long as motion endures moderate nutrition and ventilation with air will not be lacking, especially since with sufficiently great force the flame is able to attract air equally as well as nutriment; which is shown as concerns nutrition by Cardano’s lamps,  and as concerns air by the registers of furnaces.   We will make use therefore either of a flame, or of any other thing bearing an analogy to a flame to this extent at least, that it arouses a boiling in fluid, and always feeds upon the new matter that is attracted.  It is evident furthermore what sort of thing the fixed Stars or the Sun bring about in the World: and what is needed is not light, nor even any heat, but only the matter for an enduring battle, which cannot obtain without the influx of new matter. For certain Chemists promise perennial motion in vitro, to which they include a certain most strong liquor together with a matter to be devoured; it is nevertheless necessary that, once the reaction is completed, it be exhausted in due time.

EXPERIMENT ON ANIMALS CONFIRMS THIS WITH RESPECT TO PYROPUS, THE MOTION OF THE HEART AND OF THE BLOOD, RESPIRATION

By experiment, as well equally as by the agreement of authors, it is evident that there is, moreover, something in animals similar to a flame, or, if you please, to the Sun or to a fixed Star, and of course not to mention a certain newly discovered pyropus or nearly perpetual corporeal light furnished from the liquor of the human body, which through motion brings about a most violent fire; of course it is manifest to the senses themselves that in many animals there occurs a great heat, at least around the heart --although it be well known that cold ebullitions are produced, for us any ebullition will suffice--. There circulates through the vessels of the body moreover a certain liquor that is called ‘blood’, which boils with so much force as to expand exceedingly the capacity of the heart, which brings it about furthermore that the heart, not without a cooling impetus towards dilating --as elastica are accustomed to bringing about--, again contracts itself by nearly the same force by which the heart was dilated through the tonus of its parenchyma  (for the heart is muscular and fibrous),  and in turn expels the blood-- by another route nevertheless, since the valvule is blocking the return along the route by which it entered.  For which reason, moreover, it is plausible that by motion a new ebullition is prompted, just as we see things that are agitated or placed in a hot place boiling more forcefully.  And while it is granted that the seat of effervescence is in the heart, it nonetheless is easily communicated to the whole body by the blood vessels, just as [when] we attempt to heat an enormous cask of wine with a small fire, if the fire be applied through a small copper utensil, connected with the vessel through a tube.  Seeing moreover that in any ebullition there is an excessive dilatation, the vapor is nevertheless not expelled, but rather it is necessary that it in turn be pushed along, whence arises respiration, indeed in all exceedingly great efficient [causes] there is a certain reciprocation of restitutions such as we note in oscillating pendula, or in vibrating chords.  And ventilated furnaces exhibit a certain parallel to respiration, whenever they are thus tempered so that by turns they now attract air, and now expel smoke through the same aperture. 

THE AGREEMENT OF AUTHORS; AND IN WHAT WAY EBULLITION MAY HAPPEN IN SEVERAL THINGS

We also have the agreement of the authorities: many indeed think that it is the Hot in the body that is fed by the humid; some appeal to the little flame in the heart, others to the fire without light,  a certain I-know-not-what analogous to the elements of the stars, as much as [to say] that in reality everything is a flame; some say it is a certain fermentation, some that it is innumerable little explosions comparable to gunpowder: we think that in all of these a moderate and enduring boiling obtains, which is fed by a circulating matter that grows more and more rarefied and is also restored little by little.  Indeed, in all liquid bodies --where there are contained heterogeneous bodies, diverse with respect to degree of density, dilatable, variously mixed with condensable bodies, and contained by bonds-- there is ebullition, as they are thus liberated so that they may act upon one another; of this we have said much in our Hypothesis.  This is indeed true, so that even glasses, and indeed fused metals and metals reduced to a liquid state, should themselves at length boil intensely; but ebullition endures the longest when from the beginning it is not everywhere equal, but rather, with the first parts having been consumed, the neighboring parts are little by little attracted to the seat of the ebullition, or by the circulation that is brought about all of the parts are subject to enter into the fire little by little, such as we see happening in a flame, and as remains hidden from us in the body of an animal.  We will thus rightly assert that an animal is not only a Hydraulico-Pneumatic machine, but also in a certain respect a Pyrotechnic one.   

MOVEMENT OF THE ANIMAL FROM ONE PLACE TO ANOTHER; THANKS TO WHICH BONES AND FLESH

Yet to obtain perpetuity it does not suffice to have a Liquor on which the ebullition feeds for some time, for however great is the capacity of the lamp, which at any rate must be fairly small, the oil will soon be consumed: a lamp is therefore required for our Machine, which will seek out for itself and pour its own oil; or indeed, if it now lights upon no ready oil, it will know how to obtain this from olives that it gathers;  in reality, an animal is indeed such a machine.  As therefore the entire Machine must be moved with respect to place, it is necessary that the liquid be included within the firm part or the vessel, and from there it is necessary that the liquor be able to move the vessel itself in which it is contained, as indeed at length the enclosed vessels are ruptured by ebullition if they do not swell up.  They are able moreover to extract something from the swelling; thus with one part inactive and restrained, another part will be moved forward, whence if done by alternations a progression arises.  It is however necessary that the force of ebullition be superior to the weight of the body; the whole can indeed be thrust forth by a part that has been pushed into something that offers resistance, as comes to pass in leaping, swimming, and flying.  Whence it is fitting that the hard parts be interwoven with the soft ones, and that the hard ones themselves be disposed to various motions through their various joints.  These hard parts are called bones in animals, while the soft parts both convey, renew, and purify the boiling liquor, as well as removing that most subtle vapor that arises therefrom and by whose motion they swell, whence the flesh that is composed by the vessels and separating sieves of both the liquors as well as of the vapors or spirits. 

HOW THE ANIMAL MAY BE INCITED TO ACTING BY EXTERNAL AND INTERNAL OBJECTS; AND OF THE ORGANS OF THE SENSES

As moreover the vessels of the spirits, and of course the nerves and membranes and the adhering muscles, variously press upon one another through the force of the spirits that inflate the vessels and are sent out and moved by the boiling of the blood, at length everything is arranged in equilibrium; neither are they able to grow more inflated, nor are they able to be pressed more [by] those most closely bordering them; which should come to pass moreover when several vesicles confusedly pressing upon one another in a single closed space, from a single blow of a bellows through flexible tubes (similar to those that are now occasionally used for the water that is sprayed during fires), I grasp that they simultaneously swell up and mutually press upon one another.  When to be sure a certain inequality has arisen from an external or an internal cause, which happens when an animal’s senses are aroused, thereupon the entire force of the breath pushes either towards a restitution or, when it can not do this, towards an offsetting of very short duration, which, since often, on account of the structure or the present location of the parts, cannot be obtained without tremendous upheaval.  Hence at length there arises from a small cause a great motion in the animal, since the cause of motion is always at hand to the thing to be moved, and awaits release, just as is the case when someone opens a faucet and enables the water’s exit, or releases a tense bow, or lights gunpowder: he does not in fact apply a force, but rather takes away an impediment. 

IN THIS WAY [ARISE] SENSE AND APPETITE, AND THE UNION BETWEEN THE SOUL AND THE BODY; AND IN WHAT WAY THE SOUL IS ENTIRELY IN EVERY PART`

It is well known furthermore in what way an animal’s force is entirely in the whole and entirely in any given part, which however obscure it appeared hitherto, nevertheless now, with our explanation duly considered, is easily discovered.  Take for instance the vesicles inflated by a bellows, described above; thereafter, once all are arranged in equilibrium, so that one be not able to yield more to the other, any given vesicle will receive all of the force of the blowing, and indeed if it has less tenacity in one small part of the membrane than the total force of the blowing, this vesicle will rupture from the total force of the blowing that is being applied.  And whoever indeed wishes to compress one vesicle will experience all of the force that had dilated the bellows offering resistance to him. Since moreover we will at length demonstrate [that] force is one thing, motion quite another, and motion indeed inheres in an extend mass, while motive force inheres in a certain other subject, which is called in common bodies the substantial form, in living bodies the Soul, in Man the Mind, whence in animals the origin of sense as well as appetite, and the union of the soul and the body, and the way in which either the Soul acts in the body, or is acted upon by the body will be able to be explained with unexpected clarity.  What has been bestowed to the human Mind, from which there follows an immortality conjoined with memory (as indeed whoever [agrees] to accept immortality without reminiscence has nothing much to look forward to) we will discuss in another place.

UNATTACHED MARGINALIA ON MANUSCRIPT PAGE 1:

Since it is exceedingly difficult for us to explain the efficient cause or the mode of generation, we are oft times able to make use of the final cause, for nothing is without a certain effect.  And this effect is the end of the cause.  Nature need not make particular decisions, it suffices in any case that not consider the outcome, and that from infinite vain attempts only the good combinations should follow, with the author of all of nature guiding everything to perfection. 

UNATTACHED MARGINALIA ON MANUSCRIPT PAGE 3:

(see Bartholin’s Anatomia, Book 2, Ch. 6, p. 383,  where he undertakes to show that it is the pulsific faculty at work here, which [is] nothing other than the elastic force.)

Whence the reason of the phenomenon that confuses the Anatomists is rendered, [namely], why the pulse is fairly equal although the influx of blood be unequal, since evidently any given elastic bodies upon which pressure is exerted so that they move swiftly or slowly, nevertheless always restore the same speed, inasmuch as their tone permits them, whence indeed the isochronism of vibrations, and the quality of sound has elsewhere been described by us.  For which reason with a relaxed tone, so that on account of [one’s] debilitated condition during fevers the pulse can be weaker although the influx of blood is made faster, wherefore the pulsific faculty of the heart, which indeed nowadays distinguished Anatomists nevertheless defend (see Bartholin, Anatomia reformata, Book 2, Ch. 6, p. 383),  is nothing other than the elastic force. 

Comments

[Louis Vuitton Stores]

i went to the same school as patrick. i remeber those girls from my school who wrote in. they were white trash...i always felt so bad for them.