In the Bodies of Animals ‘tis oftentimes allowable for a Naturalist, from the manifest and apposite Vses of the Parts, to Collect some of the Particular Ends to which Nature, destinated them. And in some cases we may, from the known Natures as well as from the Structure, of the Parts, ground probable Conjectures (both Affirmative and Negative) about the Particular Offices of the parts,
To obviate mistakes, you may please to take notice, both That in this Proposition, I speak only of those Ends and Uses of the Parts of an Animal, that relate to the Welfare and Propagation of the Animal it self, and which therefore I formerly call’d Animals Ends: and yet that I do not thereby deny any Declaration that is made in the H. Scriptures, That God design’d that the Entire Animals, as well as their Parts, should be in several ways serviceable to Man. And haveing premis’d this to explain my meaning in the Proposition, I shall now consider distinctly the two parts whereof it consists.
And 1. There is no Part of Nature known to us, wherein the Consideration of Final Causes may so justly take place, as in the Structure of the Bodies of Animals. And I confess, that when I assist at a well-administer’d Anatomy, I do so wonder at the admirable Contrivance of a Humane Body, that I cannot but somewhat wonder, that there should be found among Philosophers, men that can ascribe it to blind Chance The Stoick, that in Cicero asked an Epicurean, why Chance did not make Palaces and other Buildings, seems not to me to have made an impertinent Question. For the commodiousest Houses Mens Bodies dwell in, are far less curious Structures, than the Mansions their Souls reside in: which you will not think a groundless Paradox, if you consider, that, whereas even in a Palace, the Materials being Wood, Stone, Brick, Mortar, Glass, and four or five Metals, are but Few in comparison of the Parts of differing Textures, as Bones, Nerves, Ligaments, Membranes, Muscles, Veins, Arteries, Grissels, Glandules, Jellys, Humours, and their Disposition is exceeding Slight, in comparison of the curious and elaborate Contrivance of the numerous Parts, both solid and fluid, of the Human Body: whereof tho’ the Stable Parts alone have been reckon’d to amount to some Hundreds; yet in Every One of these parts, the Bulk, Figure, Consistence, Texture, Situation, Connexion and Aptness for motion, is the most Commodious that can be devised; and All of them are wonderfully Symmetrical, both to, one another and the whole Body; To divers of whose Motions, as Leaping, Running Speaking, Swimming, Sneezing &c. a great Number of them conspire. And this Number of Parts is so artificially contrived and pack’d together, that tho’ in a Body where no room is lost, many Parts do at the same time exercise very differing Motions, yet each of them moves freely, and does not at all Hinder another, but rather they Promote each others Motions.
I will not suffer Indignation to transport me so far as to wish, That those that deny the Usefulness of all the Parts of their Bodys may fall Sick, or receive some Wound, to be thereby at once Convinc’d and Punish’d: But I will venture to say, that Diseases or Hurts alone may shew, how excellently all the Parts of our Bodys are Contriv’d in order to our Welfare. For, if so much as a Finger be made Bigger by Tumors, or Displac’d by being put out of Joynt, or kept in a Wrong Posture by Contractions, or have its Continuity violated by Cutting, or its Tone chang’d by Strains or Contusions, or its Sense or Motion taken away by the Palsey, or its Membranes fretted by Sharp Humors, or its Motions Disorder’d by the Cramp or Convulsions, In any of these Cases we quickly find, how Commodiously the Parts Affected were Framed or Dispos’d, when any Disease or Hurt gives them a Preternatural Constitution; that is, changes that Figure, Connexion, Tone, &c, which, according to the Institution of Nature, whilst the Body is in full Health, does belong to it.
The Eye (to single out again that Part for an Instance) is so little fitted for almost any other Use in the Body, and is so exquisitely adapted for the Use of Seeing, and That Use is so necessary for the welfare of the Animal, that it may well be doubted, whether any Considering Man can really think, that It was not destinated to that Use. The six or seven Muscles that move the whole Bulbe of the Eye, upwards, downwards, to the right Hand, to the left, and to various oblique Positions; and the several Coats and Humors that make up the Sensory, Have not only their Bigness, Shape, Consistence, Situation and Connexion admirably Adapted to that End; but the Transparency of the Cornea and the Humors, the Opacity of the Vvea, and the Semiopacity of the Retina, and the several Motions of the Parts of the Eye, being requisite to Receive, Transmit, Refract, and Dispose the Visive Beams that come from the Object, after the manner requisite to make the Liveliest Picture of it in the Bottom of the Eye, Do no less concur to Compleat this matchless Organ of Vision: which is so rarely Contrived in order to That Use, and comparatively so little to any Other, that there is no more Rashness to say, that an Eye, than that a Telescope, was made for an Instrument to See with; that is, to Discover the Colours, Magnitudes, Shapes and Motions of Distant Objects. And in that admirable Perforation of the Vvea, which we call the Pupil, Nature has much outdone Art. For whereas We are fain to apply to the Object Glasses of Telescopes, Opacous Bodys with several Circular Apertures, that Some may let in less Light, and Others more, according as the Objects are more or less Bright or Inlighten’d; That part of the Vvea that hangs in the Aqueous Humor, is an Aperture, as the Artists call it, that Narrows and Opens it self in a trice, according to the exigency of the Objects we look on; Which if they be so constituted or plac’d, that they Reflect but a Dim Light, the Curtain is presently drawn Open, and the Pupil circularly Widen’d, to let in the more Beams of Light; and the Contrary happens, as often as the Object, being too Luminous or Illustrated, would offend the Organ, or disturb the Sight, if the Contraction of the Pupil did not shut out some of Its Beams. But for the Uses of the several parts of the Eye, I shall referr you to the Industrious Jesuit Scheiner’s Oculus, and Des Cartes his excellent Dioptricks; where you will easily perceive, that, in Framing the Eye, Nature did not only act with Design, but with so much Skill in Opticks, that a more than ordinary insight into that Science, is necessary to Understand the Wisdom of the Contrivances; and perhaps no degree of Skill in it, would enable a man to Alter them for the better. ‘Twere tedious to mention the Other Parts of the Body, that manifestly appear to have been preordain’d to certain Uses. The Books of Anatomists are full of Passages applicable to this purpose; of which I shall say in general, that, tho’ what they deliver suffices to shew, That all the Parts of the Body are the Effects of an Intelligent Cause: yet, unless their Descriptions and Reflexions be improv’d by Men vers’d in Mathematicks and Mechanicks, and, I shall venture to add, in Chymistry too; we shall but imperfectly understand, how Intelligent that Cause is, or how much Wisdom it has display’d, in the Structure of a Human Body and each of its parts.