with teeth, which other birds want, to chew his food, and thereby pre- PHYSICS. pare it for digestion; he needs no crop, or fuch a strong mufcular ftomach, as is ufually found in birds.

In fhort, to omit the peculiar ftructure of other internal parts, wherein the bat differs from other birds; fince the female was not, like them, to be oviparous; but, like mice, and other quadrupeds, to bring forth her young ones alive; fhe is not only furnished with an uterus, fitted for that purpose; but, in regard she does not exclude, together with the fœtus, a competent ftock of aliment, to nourish it, till it can fhift for it felf; the bat is furnished with teats to give fuck: and 'tis obferv'd, that as she has but two of thefe, fo fhe brings forth but two young ones at a time; while mice are much more prolific.

The writers of natural hiftory, and travellers, afford numerous inftances of the various, and excellent contrivances, that are to be found in animals differing from man, in the fabric of the mouth, and other parts, fubfervient to the preparation and digeftion of their aliment.

But, to be filent, as to the mouths of tortoifes, camelions, &c. the hardness of whofe gums, with regard to their aliment, fupplies the want of teeth, there is an American beaft, which ferves as a notable inftance, to manifeft how the wife architect can compenfate the want of teeth, by the rare ftructure of the mouth and tongue; and their fitness to seize, and make use of that aliment, which, tho' uncommon for a beaft of his bulk, he feems to have been deftined to live upon. The animals of this kind are, by Hernandus, call'd, Achoas, and Tamendoas; and, of thefe, he says, "they are quadrupeds, about the fize of lambs, whofe bellies almost "touch the ground; that they have no teeth at all, but live upon ants; "whofe hillocks they turn up with the two large claws they have fixed "to their fore-feet, and then thrusting out their long rough, cylindrical tongue, they roll it upon as many as they can, and fo draw them into "their mouth, which is exceeding narrow." Pife adds, that "their "tongue, which is fometimes two feet in length, lies doubled up in a cavity, between the fides of the lower jaws; which, in order to catch "their prey, they thrust into the trunks of trees, and there fuffer it to "continue, with a moisture upon it, till cover'd with ants; and then fuddenly draw them with it into their mouths."

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'Tis alfo to be confider'd, that many things may be useful, in an organical part, befides thofe whereby its office is primarily and chiefly perform'd. Thus, tho' the eye-lids, and their motions, together with the little glands that belong to them, are not at all neceffary to the act of vifion; yet they are to the compleatnefs, and welfare of the eye: as is manifeft by the pain and prejudice that organ receives, if the eye-lids be confiderably disorder'd.

But, befides those uses of the parts of a human body, which I call ana tomical, because they are fuch as anatomifts have difcover'd, by mere diffection; there may be feveral others, which I term chymical, because these parts prepare spirits of feveral forts, and, perhaps, perform other

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PHYSICS. operations, very important, if not neceffary, to the welfare of a living

man.

And there may still be other uses, very proper to be confider'd, in fome parts of a human body; as the mechanical advantages for which the various fhapes and ftructures of different mufcles, the feeming irregular fabric of the bones, and efpecially of the proceffes and protuberances, are admirably fitted; and in fome parts too there are peculiar ones: as for inftance, optical ones in the eyes, which must be confider'd, before the defign of nature therein can, without rafhnefs, be cenfured.

Thus tho' the figure of the cryftalline humour be much more fpherical in moft fish than in men, and other terreftrial animals; yet he who understands the doctrine of refractions, and confiders that fish under water are to see thro' a far thicker medium than air, will readily acknowledge that this difference between their eyes, and those of men, is not an imperfection in the former, but, whilft thofe creatures are in their own element, a great advantage.

And, to be fhort, I think there are fo many fciences, and other parts of knowledge, fome of them perhaps fcarce yet difcover'd, that discover'd, that may be requifite to warrant a man in cenfuring the ends of God, in the bodies of animals, that very few men are qualified to condemn them juftly; and those who have knowledge enough to judge right, will not be forward to condemn, but admire them. Thus men may eafily be too rafh, in thinking a part inartificially framed, upon fuppofition that by the anatomical diffection of it they know all the ufes whereto the skill of the divine artist could defign it.

And it will not neceffarily follow, that because in fome particular bird, or beast, or fish, we are unable to fay why this or that part is not to be found, or why it is otherwife framed or fituated than that which is analogous thereto in man; it must therefore be cafually or undefignedly framed, or placed; fince we cannot expect, from brute animals, anfwers to those proper questions about their own bodies, which we can receive from men about theirs. Nay, notwithstanding the great diligence with which the more curious phyficians are obliged to cultivate anatomy, and the frequent opportunities they have to do it, and to inquire of living men about what they observe, and feel, when the natural use of their parts is hinder❜d'or perverted; yet we are to this day at a lofs as to the true uses of the visible parts of the body, to fay nothing of the invifible ones. So that 'tis no wonder if in animals, whofe fabric we have much less concern to inquire into, and much lefs opportunity to examine, we fometimes find parts, of whofe ufes and fitnefs men are hitherto unable to give a fatisfactory account. For even in man himself, tho' there be numerous valves found in his veins, yet for those many ages that the true uses of them were unknown, an Epicurean phyfician might have thought he had reafon to look upon them as fuperfluous parts; which, fince the circulation of the blood is difcover'd, are acknowledg'd of the greatest utility.

And, fince God is both a moft free, and a most wise agent, it need not PHYSICS. feem ftrange that he should adorn some animals with parts or qualities that are not neceffary to their welfare, but that feem defign'd for their beauty; fuch as the difpofition of the camelion to change his colour, and the lovely green, blue, yellow, and other vivid colours, that adorn fome forts of pigeons, parrots, and the fmaller birds, and especially that admirable little creature the humming-bird.

On the other fide, God's wifdom fometimes feems to be provident, and follicitous, not to bestow on an animal, or a part of it, more than is neceffary for the ufe whereto either is defign'd. Thus the veins are by anatomifts obferv'd to have but one coat, and ufually to lie more expofed than the arteries that accompany them, which have ftronger, and double coats, because they are to convey a more important liquor, which liquor, befides that 'tis more agitated and fpirituous, is forcibly impell'd into them, by the strong mufcular contraction of the heart. And 'tis obfervable, that tho' the nerves ufually lie deep, to be kept both fafe and warm, being very liable to be offended both by cold and the contact of external bodies; yet as 'tis neceffary that the optic nerve should expand itself into the eye, the membranes which inveft that nerve, and other coats of the eye, except the retina, are made vastly more firm than the Dura, and the Pia mater, whence they proceed; and tho' exposed to the free air, are lefs fenfible of the cold than most parts of the body, and will bear, without danger, feveral liquors, and other offenfive things, whofe pungency would put other nerves. of the body into convulfive motions.

This conduct makes it feem as if God, like an excellent writing-mafter, did in the great volume of his creatures intend to bestow on fome of them things rather ornamental than neceffary, as flourishes on the capital letters of nature; and sometimes to employ characters of different shapes, to ftand for the fame letters; and fometimes, alfo, to employ abbreviations, to express, in fhort, that which might be very juftifiable, had it been more fully delineated.

And if we allow, as 'tis very probable, that God defign'd, by the great variety of his works, to display to his intelligent creatures the great abundance of his wifdom; 'tis obvious that much of the variety obfervable in the analogous parts of animals, may be very conducive to fo comprehenfive a view; whereto the beauty of fome creatures, and parts, as well as their more neceffary or convenient ftructure, may be fubfervient; efpecially if the innocent delight of man be alfo intended, as it feems to be, in the curious colours and fhapes of feveral flowers, in the melodious mufic of birds, and in the vivid and curiously variegated colours of the feathers of several winged animals; particularly thofe that make up the peacock's

train.

'Tis worth our obferving, that we are not near fuch competent judges of wisdom, as of juftice and veracity, which are estimated by eternal and fixed bounds, or rules, very intelligible to a moderate understanding. But as for wisdom, the more profound it is, the lefs we are able to look

thro'

PHYSICS. thro' it, penetrate to the bottom of it, and judge knowingly of its actions. And therefore, tho' we may fafely conclude, that God acts wifely, when he does any thing that has an admirable tendency to those ends, we justly suppose him to have defign'd; yet we cannot fafely conclude in the negative, that this, or that is unwife, because we do not difcern a wife tendency therein. For fo wife an agent may have other designs than we know of, and further aims than we can difcern, or fufpect; and may have at hand, or furnish himself with fuch means to compass his ends, and that even by the co-operation of what we think useless, or improper, as are far above the reach of our conjectures; and without the knowledge of which, we rafhly cenfure the wifdom of his proceedings.

In the double horizontal dial, formerly mention'd, it would be rafh of any to condemn, or defpife, the various lines they find traced upon that useful instrument, because they fee they are not neceffary to fhew the hour of the day; fince the mathematician, who drew thofe lines, may be well fuppofed to have more ends than one, or two, in making the inftrument; and not to have drawn them by chance, or unskilfully, tho' the inconfiderate cenfurers do not know for what other, or farther purposes, the artist may have defign'd them.

Suppofe fome Indian fisher-man, unacquainted with European arts and affairs, should come on board a man of war, under fail; he would quickly perceive, by the ufe made of the tackling, that this floating building was very artificially contrived; yet, if he should fix his eyes upon one of the guns, or the anchors, and perceive that no ufe was made, or likely to be made of them, in failing, he would be strongly tempted to think, that those heavy maffes were useless clogs, and burdens to the veffel. But if he were told the neceffity, and ufefulness of the guns, for defence; and of the anchors, to ftay the fhip in ftorms; he would prefently alter his mind, and confefs, that he had blamed the contrivers for that, which nothing but his ignorance kept him from commending.

I have dwelt the longer on this third propofition, because I think it a duty, that our reafon owes to its author, to endeavour to vindicate his manifold wisdom, in this libertine age; wherein too many, who have more wit than philofophy, labour upon Epicurean, and fome even upon Cartefian principles, to depreciate the wifdom of God; whilft others prefume to cenfure his contrivances, in the bodies of animals.

I had also a defire, that the reader fhould not barely obferve the wifdom of God, but actually be convinc'd of it. To which purpose, in my opinion, 'tis very conducive, if not neceffary, befides general notions, to observe, with attention, fome particular inftances of the divine skill, wherein it is confpicuously display'd. 'Tis true, that in the idea of a Being infinitely perfect, boundless wifdom is one of the attributes included: but, for my part, I am of opinion, that this general and indefinite idea of the divine wifdom, will not give us fo great a veneration for it, as may be produced in our minds, by knowing, and confidering the admi

rable contrivances of the particular productions thereof; and exqui- PHYSICS. fite fitness for those ends and uses, to which they appear to have been defign'd.

PROP. IV.

We ought not to be hafty in concluding upon the particular use of a thing, or the motive which induced the author of nature to frame it in a peculiar manner.

It has been already fhewn, that fome parts are fo excellently, and manifeftly fitted for a certain ufe, and fo much better adapted to that, than to any other; as to make it feem perverfe, to doubt of its being defign'd thereto. But the like cannot be faid, in general, of all the parts of the body; especially of the internal. There are many ufes, either neceffary, or highly conducive to the welfare of the animal, that have no part fo much more confpicuously fitted for them than another, as to leave it easy to determine the true, and primary offices thereof; efpecially, with fo much certainty, as thereon to ground philofophical inferences. And, of this difficulty, I conceive, there may be four reafons; tho' they do not all occur in each particular cafe.

And, firft, the whole animal itself, that we confider, is a part of the universe; and, therefore, cannot well be fuppofed to have been framed, and furnish'd with the parts it confifts of, merely for its own fake. And, when we say, that all its parts are contriv'd to the beft advantage to the animal; I conceive, this is to be fo understood, in a limited fenfe; that the parts are excellently framed for the welfare of the animal, as far as that welfare is confiftent with the general ends of the author of nature, in the constitution, and government of the univerfe; which ends, because they relate to the whole world, I call cofmical. It has not, indeed, been prov'd, that none of these cofmical ends are discoverable by us: however, to discover them all, is no eafy task. Yet, it feems prefumptuous to fuppofe, that the welfare of particular animals is any farther defign'd, and provided for, than will confift with the cofmical ends of the universe, and the courfe of God's general providence; to which his particular providence ought, in reason, to be fubordinate. And, tho' it seems great rafhnefs in men, to determine pofitively, and exclufively of others, what ends the omnifcient creator propofed to himself, in giving to the world its prefent frame; yet, as far as I can hitherto difcern, I fee nothing more likely to have been one grand motive of fo great a variety, as we obferve in his corporeal works, especially in animals, than that he might, by fo many very different contrivances as are to be met with in the ftructure of men, quadrupeds, birds, fish, reptils, &c. exercife and difplay his manifold wifdom. As man, even upon account of his body, is acknowledg'd the most perfect of animals; if God had barely defign'd to give every creature the most advantageous ftructure, it feems, that he fhould have made no other animals than men. But, then, there could not have been that diverfity of contrivance among living automata, which fo greatly recom

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