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CHAPTER VI.

THE ARGUMENT CUMULATIVE.

WERE there no example in the world of contrivance except that of the eye, it would be alone sufficient to support the conclusion which we draw from it, as to the necessity of an intelligent Creator. It could never be got rid of; because it could not be accounted for by any other supposition, which did not contradict all the principles we possess of knowledge; the principles according to which things do, as often as they can be brought to the test of experience, turn out to be true or false. Its coats and humours, con

[The figure is introduced to remind the reader of the fine adjustment of the eye; a subject explained in the Appendix:-A, B, is the object, and the lines represent, the light reflected from it into the eye. On the surface of the cornea, which is the transparent part of the eye,

the rays are in a certain degree refracted. Passing through the coat called cornea, they enter the aqueous humour. In their transmission through it, they pass into the pupil. They enter the lens or crystalline humour, and by the greater power of refraction in this humour, the rays are drawn to a point and impinge on the bottom of the at A, B. It will be further seen that the rays coming from B are refracted to a, those from A to b, and that the image is therefore represented inverted.]

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structed as the lenses of a telescope are constructed, for the refraction of rays of light to a point, which forms the proper action of the organ; the provision in its muscular tendons for turning its pupil to the object, similar to that which is given to the telescope by screws, and upon which power of direction in the eye the exercise of its office as an optical instrument depends; the further provision for its defence, for its constant lubricity and moisture, which we see in its socket and its lids, in its glands for the secretion of the matter of tears, its outlet or communication with the nose for carrying off the liquid after the eye is washed with it; these provisions compose altogether an apparatus, a system of parts, a preparation of means, so manifest in their design, so exquisite in their contrivance, so successful in their issue, so precious, and so infinitely beneficial in their use, as, in my opinion, to bear down all

doubt that can be raised upon the subject 21. And what I wish, under the title of the present chapter, to observe, is, that if other parts of nature were inaccessible to our inquiries, or even if other parts of nature presented, nothing to our examination but disorder and confusion, the validity of this example would remain the same. If there were but one watch in the world, it would not be less certain that it had a maker. If we had never in our lives seen any but one single kind of hydraulic machine, yet, if of that one kind we understood the mechanism and use, we should be as perfectly assured that it proceeded from the hand and thought and skill of a workman, as if we visited a museum of the arts, and saw collected there twenty different kinds of machines for drawing water, or a thousand different kinds for other purposes. Of this point each machine is a proof independently of all the rest. So it is with the evidences of a Divine agency. The proof is not a conclusion which lies at the end of a chain of reasoning, of which chain each instance of contrivance is only a link, and of which, if one link fail, the whole falls; but it is an argument

21

Again we have reference to the structure of the eye; which shows the necessity of throwing our observations on this organ into the Appendix.

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separately supplied by every separate example. An error in stating an example affects only that example. The argument is cumulative, in the fullest sense of that term. The eye proves it without the ear; the ear without the eye. The proof in each example is complete; for when the design of the part, and the conduciveness of its structure to that design is shown, the mind may set itself at rest; no future consideration can detract any thing from the force of the example.

CHAPTER VII.

OF THE MECHANICAL AND IMMECHANICAL PARTS AND FUNCTIONS OF ANIMALS AND VEGETABLES.

It is not that every part of an animal or vegetable has not proceeded from a contriving mind; or that every part is not constructed with a view to its proper end and purpose, according to the laws belonging to, and governing the substance or the action made use of in that part; or that each part is not so constructed as to effectuate its purpose whilst it operates according to these laws; but it is because these laws themselves are not in all cases equally understood-or, what amounts to nearly the same thing, are not equally exemplified in more simple processes, and more simple machines, that we lay down the distinction, here proposed, between the mechanical parts of animals and vegetables."

22 The observation here is most sensible. When we speak of an organ as peculiarly suited to exhibit design, we mean merely that we comprehend something of the object of the particular structure. But there is no part of an animal, if we fully comprehended what was necessary to the performance of its functions, that would not raise

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