ARGUMENT OF DESIGN 97 



cording 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, constructed, 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 direc- 

 tion in the eye the exercise of its office as an optical 

 instrument depends ; the farther provision for its defence, 

 for its constant lubricity and moisture, which we see in 

 its socket and its lids, in its gland 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 success- 

 ful in their use, as, in my opinion, to bear down all doubt 

 that can be raised upon the subject." 



Had Paley lived now he could have added a great 

 deal more. He would probably have compared the eye 

 with a photographic camera, for it is a dark chamber 

 with the lens in front and a sensitive plate at the back : 

 upon which the external image is focussed as a minute 

 picture in a similarly inverted position. From this plate 

 (the retina) the optic nerve carries the vibrations to the 

 brain, where the picture is reversed, and the sense of 

 vision beholds, not the tiny image at the back of the 

 eye, but its source outside, as a house, in its proper 

 dimensions. 



Can all this and much more be acquired by chance 

 variations, the few which are favourable occurring from 

 time to time ? Indeed, there is no guarantee that they 

 will occur at all in the succeeding generations ; when 



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