In all cafes, wherein the mind feels itfelf in danger of being confounded by variety, it is fure to reft upon a few ftrong points, or perhaps upon a fingle inftance. Amongft a multitude of proofs, it is one that does the bufinefs. If we obferve in any argument, that hardly two minds fix upon the fame inftance, the diverfity of choice fhews the ftrength of the argument, becaufe it fhews the number and competition of the examples. There is no fubject in which the tendency to dwell upon felect or fingle topics is fo ufual, becaufe there is no fubject, of which, in its full extent, the latitude is fo great, as that of natural hiftory applied to the proof of an intelligent Creator. For my part, I take my ftand in human anatomy: and the examples of mechanifm I fhould be apt to draw out from the copious catalogue which it fupplies, are the pivot upon which the head turns, the ligament within the focket of the hip joint, the pulley or trochlear mufcle of the eye, the epiglottis, the bandages which tie down the tendons of the wrift and inftep, the flit or perforated mufcles at the hands and feet, the knitting of the inteftines to the mefentery, the courfe of the chyle into the blood, and the conftitution of the fexes as extended throughout the whole of the animal creation.

Were there no example in the world of contrivance except that of the eye, it would be alone fufficient to fupport the conclufion which we draw from it, as to the neceffity of an intelligent Creator. It could never be got rid of: becaufe it could not be accounted for by any other fuppofition, which did not contradict all the principles we poffefs of knowledge; the principles according to which, things do, as often as they can be brought to the teft of experience, turn out to be true or falfe. Its coats and humours, conftructed, as the lenfes of a telefcope are conftructed, for the refraction of rays of light to a point, which forms the proper action of the organ; the provifion in its mufcular tendons for turning its pupil to the object, fimilar to that which is given to the telefcope by fcrews, and upon which power of direction in the eye, the exercife of its office as an optical inftrument depends; the further provifion for its defence, for its conftant lubricity and moifture, which we fee in its focket and its lids, in its gland for the fecretion of the matter of tears, its outlet or communication with the nofe for carrying off the liquid after the eye is wafhed with it; thefe provifions compofe altogether an apparatus, a fyftem of parts, a preparation of means, fo manifeft in their defign, fo exquifite in their contrivance, fo fuccefsful in their iffue, fo precious and fo infinitely beneficial in their ufe, as, in my opinion, to bear down all doubt that can be raifed upon the fubject.

I Believe that all the inftances which I fhall collect under thus title, might, confiftently enough with technical language, have been placed under the head of Comparative Anatomy. But there appears to me an impropriety in the ufe which that term hath obtained: it being, in fome fort, abfurd, to call that a cafe of comparative anatomy, in which there is nothing to “compare;” in which a conformation is found in one animal, which hath nothing properly anfwering to it in another. Of this kind are the examples which I have to propofe in the prefent chapter; and the reader will fee that, though fome of them be the ftrongeft, perhaps, he will meet with under any divifion of our fubject, they muft neceffarily be of an unconnected and mifcellaneous nature. To difpofe them, however, into fome fort of order, we will notice, firft, particularities of ftructure which belong to quadrupeds, birds, and fifh, as fuch, or to many of the kinds included in thefe claffes of animals; and then, fuch particularities as are confined to one or two fpecies.

I. Along each fide of the neck of large quadrupeds, runs a ftiff robuft cartilage, which butchers call the pax-wax. No perfon can carve the upper end of a crop of beef without driving his knife againft it.

The order may not be very obvious, by which I place inftincts next to relations. But I confider them as a fpecies of relation. They contribute, along with the animal organization, to a joint effect, in which view they are related to that organization. In many cafes they refer from one animal to another animal; and, when this is the cafe, become ftrictly relations in a fecond point of view.

An INSTINCT is a propenfity, prior to experience, and independent of inftruction. We contend, that it is by inftinct that the fexes of animals feek each other; that animals cherifh their offspring; that the young quadruped is directed to the teat of its dam; that birds build their nefts, and brood with fo much patience upon their eggs; that infects, which do not fit upon their eggs, depofit them in thofe particular fituations, in which the young, when hatched, find their appropriate food; that it is inftinct, which carries the falmon, and fome other fifh, out of the fea into rivers, for the purpofe of fhedding their fpawn in frefh water.

We may felect: out of this catalogue the incubation of eggs. I entertain no doubt, but that a couple of fparrows hatched in an oven, and kept feparate from the reft of their fpecies would proceed as other fparrows do, in every office which related to the production and prefervation of their brood.

Suppose, in the next place, that the perfon, who found the watch, fhould, after fome time, difcover, that, in addition to all the properties which he had hitherto obferved in it, it poffeffed the unexpected property of producing, in the courfe of its movement, another watch like itfelf; (the thing is conceivable;) that it contained within it a mechanifm, a fyftem of parts, a mould for inftance, or a complex adjuftment of laths, files, and other tools, evidently and feparately calculated for this purpofe; let us enquire, what effect ought fuch a difcovery to have upon his former conclufion.

I. The firft effect would be to increafe his admiration of the contrivance, and his conviction of the confummate fkill of the contriver. Whether he regarded the object of the contrivance, the diftinct apparatus, the intricate, yet in many parts intelligible, mechanifm by which it was carried on, he would perceive, in this new obfervation, nothing but an additional reafon for doing what he had already done; for referring the conftruction of the watch to defign, and to fupreme art. If that conftruction without this property, or, which is the fame thing, before this property had been noticed, proved intention and art to have been employed about it; ftill more ftrong would the proof appear, when he came to the knowledge of this further property, the crown and perfection of all the reft.

Every obfervation which was made, in our firft chapter, concerning the watch, may be repeated with ftrict propriety concerning the eye; concerning animals; concerning plants; concerning, indeed, all the organized parts of the works of nature. As,

I. When we are enquiring fimply after the exiftence of an intelligent Creator, imperfection, inaccuracy, liability to diforder, occafional irregularities, may fubfift, in a confiderable degree, without inducing any doubt into the queftion: juft as a watch may frequently go wrong, feldom perhaps exactly right, may be faulty in fome parts, defective in fome, without the fmalleft ground of fufpicion from thence arifing, that it was not a watch; not made; for not made for the purpofe afcribed to it. When faults are pointed out, and when, a queftion is ftarted concerning the fkill of the artift, or dexterity with which the work is executed, then indeed, in order to defend thefe qualities from accufation, we muft be able, either to expofe fome intractablenefs and imperfection in the materials, or point out fome invincible difficulty in the execution, into which imperfection and difficulty the matter of complaint may be refolved; or, if we cannot do this, we muft adduce fuch fpecimens of confummate art and contrivance proceeding from the fame hand, as may convince the enquirer, of the exiftence, in the cafe before him, of impediments like thofe which we have mentioned, although, what from the nature of the cafe is very likely to happen, they be unknown and unperceived by him.

It is an immenfe conclufion, that there is a God; a perceiving, intelligent, defigning Being; at the head of creation, and from whofe will it proceeded. The attributes of fuch a Being, fuppofe his reality to be proved, muft be adequate to the magnitude, extent, and multiplicity of his operations: which are not only vaft beyond comparifon with thofe performed by any other power, but, fo far as refpects our conceptions of them, infinite, becaufe they are unlimited on all fides.

Yet the contemplation of a nature fo exalted, however furely we arrive at the proof of its exiftence, overwhelms our faculties. The mind feels its power fink under the fubject. One confequence of which is, that from painful abftraction the thoughts feek relief in fenfible images. From whence may be deduced the antient, and almoft univerfal, propenfity to idolatrous fubftitutions. They are the refources of a labouring imagination. Falfe religions ufually fall in with the natural propenfity: true religions, or fuch as have derived themfelves from the true, refift it.

It is one of the advantages of the revelations which we acknowledge, that, whilft they reject idolatry with its many pernicious accompaniments, they introduce the Deity to human apprehenfion, under an idea more perfonal, more determinate, more within its compafs, than the theology of nature can do.

We have already confidered relation, and under different views; but it was the relation of parts to parts, of the parts of an animal to other parts of the fame animal, or of another individual of the fame fpecies.

But the bodies of animals hold, in their conftitution and properties, a clofe and important relation to natures altogether external to their own; to inanimate fubftances, and to the fpecific qualities of thefe, e. g. they hold a ftrict relation to the ELEMENTS by which they are furrounded.

I. Can it be doubted, whether the wings of birds bear a relation to air, and the fins of fifh to water? They are inftruments of motion, feverally fuited to the properties of the medium in which the motion is to be performed: which properties are different. Was not this difference contemplated, when the inftruments were differently conftituted?

II. The ftructure of the animal ear depends for its ufe not fimply upon being furrounded by a fluid, but upon the fpecific nature of that fluid. Every fluid would not ferve: its particles muft repel one another; it muft form an elaftic medium: for it is by the fucceffive pulfes of fuch a medium, that the undulations excited by the founding body are carried to the organ; that a communication is formed between the object and the fenfe; which muft be done, before the internal machinery of the ear, fubtile as it is, can act at all.

Whenever we find a general plan purfues, yet with fuch variations in it, as are, in each cafe, required by the particular exigency of the fubject to which it is applied, we poffefs, in fuch plan and fuch adaptation, the ftrongeft evidence, that can be afforded, of intelligence and defign; and evidence, which the moft completely excludes every other hypothefis. If the general plan proceeded from any fixed neceffity in the nature of things, how could it accommodate itfelf to the various wants and ufes which it had to ferve, under different circumftances, and on different occafions? Arkwright's mill was invented for the fpinning of cotton. We fee it employed for the fpinning of wool, flax, and hemp, with fuch modifications of the original principle, fuch variety in the fame plan, as the texture of thofe different materials rendered neceffary. Of the machine's being put together with defign, if it were poffible to doubt, whilft we faw it only under one mode, and in one form; when we came to obferve it in its different applications, with fuch changes of ftructure, fuch additions, and fupplements, as the fpecial and particular ufe in each cafe demanded, we could not refufe any longer our affent to the propofition, “that intelligence, properly and ftrictly fo called, (including under that name, forefight, confideration, reference to utility,) had been employed, as well in the primitive plan, as in the feveral changes and accommodations which it is made to undergo.”

The generation of the animal no more accounts for the contrivance of the eye or ear, than, upon the fuppofition ftated in a preceding chapter, the production of a watch by the motion and mechanifm of a former watch, would account for the fkill and intention evidenced in the watch fo produced; than it would account for the difpofition of the wheels, the catching of their teeth, the relation of the feveral parts of the works to one another and to their common end, for the fuitablenefs of their forms and places to their offices, for their connection, their operation, and the ufeful refult of that operation. I do infift moft ftrenuoufly upon the correctnefs of this comparifon; that it holds as to every mode of fpecific propagation; and that whatever was true of the watch, under the hypothefis above mentioned, is true of plants and animals.

I. To begin with the fructification of plants. Can it be doubted but that the feed contains a particular organization? Whether a latent plantule with the means of temporary nutrition, or whatever elfe it be, it inclofes an organization fuited to the germination of a hew plant. Has the plant which produced the feed any thing more to do with that organization, than the watch would have had to do with the ftructure of the watch which was produced in the courfe of its mechanical movement?

Contrivance, if eftablifhed, appears to me to prove every thing which we wifh to prove. Amongft other things it proves the perfonality of the Deity, as diftinguifhed from what is fometimes called nature, fometimes called a principle: which terms, in the mouths of thofe who ufe them philofophically, feem to be intended, to admit and to exprefs an efficacy, but to exclude and to deny a perfonal agent. Now that which can contrive, which can defign, muft be a perfon. Thefe capacities conftitute perfonality, for they imply confcioufnefs and thought. They require that which can perceive an end or purpofe; as well as the power of providing means, and of directing them to their end. They require a centre in which perceptions unite, and from which volitions flow; which is mind. The acts of a mind prove the exiftence of a mind: and in whatever a mind refides is a perfon. The feat of intellect is a perfon. We have no authority to limit the properties of mind to any particular corporeal form, or to any particular circumfcription of fpace. Thefe properties fubfift, in created nature, under a great variety of fenfible forms. Alfo every animated being has its fenforium, that is, a certain portion of fpace, within which perception and volition are exerted.

Compensation is a fpecies of relation. It is relation when the defects of one part, or of one organ, are fupplied by the ftructure of another part, or of another organ. Thus,

I. The fhort, unbending neck of the elephant, is compenfated by the length and flexibility of his probofcis. He could not have reached the ground without it; or, if it be fuppofed that he might have fed upon the fruit, leaves, or branches of trees, how was he to drink? Should it be afked, Why is the elephant's neck fo fhort? it may be anfwered that the weight of a head fo heavy could not have been fupported at the end of a longer lever. To a form therefore, in fome refpects neceffary, but in fome refpects alfo inadequate to the occafions of the animal, a fupplement is added, which exactly makes up the deficiency under which he laboured.

If it be fuggefted, that this probofcis may have been produced in a long courfe of generations, by the conftant endeavour of the elephant to thruft out his nofe, (which is the general hypothefis by which it has lately been attempted to account for the forms of animated nature,) I would afk, how was the animal to fubfift in the mean time; during the procefs; until this prolongation of fnout were completed? What was to become of the individual, whilft the fpecies was perfecting?

My opinion of Aftronomy has always been, that it is not the beft medium through which to prove the agency of an intelligent Creator; but that, this being proved, it fhews, beyond all other fciences, the magnificence of his operations. The mind which is once convinced, it raifes to fublimer views of the Deity, than any other fubject affords; but is not fo well adapted, as fome other fubjects are, to the purpofe of argument. We are deftitute of the means of examining the conftitution of the heavenly bodies. The very fimplicity of their appearance is againft them. We fee nothing, but bright points, luminous circles, or the phafes of fpheres reflecting the light which falls upon them. Now we deduce defign from relation, aptitude, and correfpondence of parts. Some degree therefore of complexity is neceffary to render a fubject fit for this fpecies of argument. But the heavenly bodies do not, except perhaps in the inftance of Saturn's ring, prefent themfelves to our obfervation as compounded of parts at all. This, which may be a perfection in them, is a difadvantage to us, as enquirers after their nature. They do not come within our mechanics.

And what we fay of their forms, is true of their motions. Their motions are carried on without any fenfible intermediate apparatus: whereby we are cut off from one principal ground of argumentation and analogy.

When feveral different parts contribute to one effect; or, which is the fame thing, when an effect is produced by the joint action of different inftruments; the fitnefs of fuch parts or inftruments to one another, for the purpofe of producing, by their united action, the effect, is what I call relation: and whereever this is obferved in the works of nature or of man, it appears to me to carry along with it decifive evidence of underftanding, intention, art. In examining, for inftance, the feveral parts of a watch, the fpring, the barrel, the chain, the fufee, the balance, the wheels of various fizes, forms, and pofitions, what is it which would take an obferver's attention, as moft plainly evincing a conftruction, directed by thought, deliberation, and contrivance? It is the fuitablenefs of thefe parts to one another, firft, in the fucceffion and order in which they act; and, fecondly, with a view to the effect finally produced. Thus, referring the fpring to the wheels, our obferver fees in it, that which originates and upholds their motion; in the chain, that which tranfmits the motion to the fufee; in the fufee, that which communicates it to the wheels; in the conical figure of the fufee, if he refer back again to the fpring, he fees that which corrects the inequality of its force.

The circulation of the blood, through the bodies of men and quadrupeds, and the apparatus by which it is carried on, compofe a fyftem, and teftify a contrivance, perhaps the beft underftood of any part of the animal frame. The lymphatic fyftem, or the nervous fyftem, may be more fubtile and intricate; nay, it is poffible that in their ftructure they be even more artificial than the fanguiferous; but we do not know fo much about them.

The utility of the circulation of the blood, I affume as an acknowledged point. One grand purpofe is plainly anfwered by it; the diftributing to every part, every extremity, every nook and corner, of the body, the nourifhment which is received into it by one aperture. What enters at the mouth, finds its way to the fingers' ends. A more difficult mechanical problem could hardly I think be propofed, than to difcover a method of conftantly repairing the wafte, and of fupplying an acceffion of fubftance to every part, of a complicated machine at the fame time.

This fyftem prefents itfelf under two views: firft, the difpofition of the blood veffels, i. e. the laying of the pipes; and, fecondly, the conftrùction of the engine at the centre, viz. the heart, for driving the blood through them.

In croffing a heath, fuppofe I pitched my foot againft a ftone, and were afked how the ftone came to be there, I might poffibly anfwer, that, for any thing I knew to the contrary, it had lain there for ever: nor would it perhaps be very eafy to fhew the abfurdity of this anfwer. But fuppofe I had found a watch upon the ground, and it fhould be enquired how the watch happened to be in that place, I fhould hardly think of the anfwer which I had before given, that, for any thing I knew, the watch might have always been there. Yet why fhould not this anfwer ferve for the watch, as well as for the ftone? Why is it not as admiffible in the fecond cafe, as in the firft? For this reafon, and for no other, viz. that, when we come to infpect the watch, we perceive (what we could not difcover in the ftone) that its feveral parts are framed and put together for a purpofe, e. g. that they are fo formed and adjufted as to produce motion, and that motion, fo regulated as to point out the hour of the day; that, if the feveral parts had been differently fhaped from what they are, of a different fize from what they are, or placed after any other manner, or in any other order, than that in which they are placed, either no motion at all would have been carried on in the machine, or none which would have anfwered the ufe, that is now ferved by it.

I Think a defigned and ftudied mechanifm to be, in general, more evident in animals, than in plants: and it is unneceffary to dwell upon a weaker argument, where a ftronger is at hand. There are, however, a few obfervations upon the vegetable kingdom, which lie fo directly in our way, that it would be improper to pafs by them without notice.

The one great intention of nature in the ftructure of plants feems to be the perfecting of the feed; and, what is part of the fame intention, the preferving of it until it be perfected. This intention fhews itfelf, in the firft place, by the care which appears to be taken to protect and ripen, by every advantage which can be given to them of fituation in the plant, thofe parts which moft immediately contribute to fructification, viz. the antheræ, the ftamina, and the ftigmata. Thefe parts are ufually lodged in the centre, the receffes, or the labyrinths of the flower; during their tender and immature ftate, are fhut up in the ftalk, or fheltered in the bud: as foon as they have acquired firmnefs of texture fufficient to bear expofure, and are ready to perform the important office which is affigned to them, they are difclofed to the light and air, by the burfting of the ftem or the expanfion of the petals: after which they have, in many cafes, by the very form of the flower during its blow, the light and warmth reflected upon them from the concave fide of the cup.