What is natural theology?

William Paley, answered from the texts and cited to the page.

William Paley answers

Natural theology is the knowledge of God obtainable by the examination of the natural world, prior to and independent of any revealed scripture. It proceeds from what we can see and handle and measure, and it asks what those things require us to conclude about the power and intelligence that produced them. The inference it makes is not a leap of faith but the same kind of reasoning we apply everywhere else.

When we find parts adjusted to one another for a purpose — the crystalline lens placed exactly where it must be placed to form an image on the retina, the cornea curved precisely as optical principles require — we conclude that intention was at work, because intention is the only cause we know that produces this kind of effect.¹ The eye is my chief example, and I press it hard: Sturmius held that the examination of the eye was a cure for atheism, and I think he was right, because what we find there is not merely something wonderful but something instrumental — made on the same principles as a telescope, correcting for the same aberrations, and surrounded by protections whose purposes are as legible as any mechanism a human artificer ever devised.²

The eyelid defends, wipes, and closes the eye in sleep; the bony socket, composed of seven different bones hollowed at their edges, lodges it in fat, the best substance for both repose and motion; the eyebrows shed moisture away from the surface like a thatched penthouse.³ And beyond all this, the nictitating membrane in birds and many quadrupeds sweeps the eye in an instant, spreads the lachrymal humour across it, defends it from sudden injury, yet does not wholly shut out the light — a combination of elastic and muscular substance, of two different kinds of action, so arranged that the muscle driving it sits safely in the back of the eye, out of the way, while a thread fine enough not to obstruct the sight communicates its contraction to the membrane.⁴

A second point, which I think is not attended to as it should be. The objection is sometimes made that we find disorder in nature alongside order, and that an intelligent principle would have produced order everywhere. The answer is that order is found precisely where it is wanted and not where it would be superfluous.⁵ The structure of the eye maintains the most exact order in the figure and position of every part; the forms of rocks and mountains and the shapes of coastlines show none, because none would have served any purpose there.

An unintelligent principle acting blindly would not discriminate in this way — it would either produce order universally or not at all.⁶ The discrimination is itself the mark of intelligence. What natural theology establishes, and what it leaves for revelation to supply, are distinct questions. It proves that there must be something in the world more than what we see, and that among the invisible things of nature there must be an intelligent mind concerned in the production, order, and support of what we observe.⁷

The particulars of that mind's character, its designs as a moral governor, the finer points of its nature as the original cause of all things — these lie beyond what the examination of hinges and membranes can reach, and I am content to leave them there.⁸ The true theist will be the first to listen to any credible communication of divine knowledge; nothing he has learned from natural theology will diminish his desire for further instruction.⁹ The two inquiries are not rivals. Natural theology prepares the mind; revelation completes it.

Sources

1. if the utility of vision to the animal which enjoys it, and the adaptation of the eye to this office, be evident and certain (and I can mention nothing which is more so), ought it to prejudice the inference which we draw from these premises

   Natural Theology

2. Sturmius held, that the examination of the eye was a cure for atheism. Beside that conformity to optical principles which its internal constitution displays, and which alone amounts to a manifestation of intelligence having been exerted in the structure

   Natural Theology

3. It is lodged in a strong, deep, bony socket, composed by the junction of seven different bones, hollowed out at their edges... Within this socket it is imbedded in fat, of all animal substances the best adapted both to its repose and motion. It is sheltered by the eyebrows; an arch of hair, which, like a thatched penthouse, prevents the sweat and moisture of the forehead from running down into it.

   Natural Theology

4. Its use is to sweep the eye, which it does in an instant, to spread over it the lachrymal humour; to defend it also from sudden injuries; yet not totally, when drawn upon the pupil, to shut out the light... it is connected by a tendon or thread with a muscle in the back part of the eye: this tendon or thread, though strong, is so fine, as not to obstruct the sight, even when it passes across it

   Natural Theology

5. Where order is wanted, there we find it; where order is not wanted, i.e. where, if it prevailed, it would be useless, there we do not find it.

   Natural Theology

6. a principle of order, acting blindly, and without choice, is negatived, by the observation, that order is not universal; which it would be, if it issued from a constant and necessary principle: nor indiscriminate, which it would be, if it issued from an unintelligent principle.

   Natural Theology

7. It is a step to have it proved, that there must be something in the world more than what we see. It is a further step to know, that, amongst the invisible things of nature, there must be an intelligent mind, concerned in its production, order, and support.

   Natural Theology

8. we may well leave to Revelation the disclosure of many particulars, which our researches cannot reach, respecting either the nature of this Being as the original cause of all things, or his character and designs as a moral governor

   Natural Theology

9. The true theist will be the first to listen to any credible communication of Divine knowledge. Nothing which he has learned from Natural Theology, will diminish his desire of further instruction, or his disposition to receive it with humility and thankfulness.

   Natural Theology