It would appear that a man must be supposed to have lost his senses before he can deny that stomachs are made for digestion, eyes to see, and ears to hear.
On the other hand, a man must have a singular partiality for final causes, to assert that stone was made for building houses, and that silkworms are produced in China that we may wear satins in Europe.
But, it is urged, if God has evidently done one thing by design, he has then done all things by design. It is ridiculous to admit Providence in the one case and to deny it in the others. Everything that is done was foreseen, was arranged. There is no arrangement without an object, no effect without a cause; all, therefore, is equally the result, the product of the final cause; it is, therefore, as correct to say that noses were made to bear spectacles, and fingers to be adorned with rings, as to say that the ears were formed to hear sounds, the eyes to receive light.
All that this objection amounts to, in my opinion, is that everything is the result, nearer or more remote, of a general final cause; that everything is the consequence of eternal laws. When the effects are invariably the same in all times and places, and when these uniform effects are independent of the beings to which they attach, then there is visibly a final cause.
All animals have eyes and see; all have ears and hear; all have mouths with which they eat; stomachs, or something similar, by which they digest their food; all have suitable means for expelling the fæces; all have the organs requisite for the continuation of their species; and these natural gifts perform their regular course and process without any application or intermixture of art. Here are final causes clearly established; and to deny a truth so universal would be a perversion of the faculty of reason.
But stones, in all times and places, do not constitute the materials of buildings. All noses do not bear spectacles; all fingers do not carry a ring; all legs are not covered with silk stockings. A silkworm, therefore, is not made to cover my legs, exactly as your mouth is made for eating, and another part of your person for the "garderobe." There are, therefore, we see, immediate effects produced from final causes, and effects of a very numerous description, which are remote productions from those causes.