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Locke and Leibniz on Armchair Teleology

[I]f we may conclude that God hath done for men all that men shall judge is best for them, because it is suitable to his goodness so to do, it will prove not only that God has imprinted on the minds of men an idea of himself, but that he hath plainly stamped there, in fair characters, all that men ought to know or believe of him, all that they ought to do in obedience to his will, and that he hath given them a will and affections conformable to it. This, no doubt, everyone will think it better for men than that they should, in the dark, grope after knowledge, as St. Paul tells us the nations did after God (Acts xvii, 27) than that their wills should clash with their understandings and their appetites cross their duty. The Romanists say it is best for men, and so suitable to the goodness of God, that there should be an infallible judge of controversies on earth; and therefore there is one. And I, by the same reason, say it is better for men that every man himself should be infallible. I leave them to consider whether by the force of this argument they shall think that every man is so. I think it a very good argument to say: the infinitely wise God hath made it so, and therefore it is best. But it seems to me a little too much confidence in our own wisdom to say, I think it best and therefore God hath made it so. And in the matter at hand, it will be vain to argue from such a topic that God hath done so, when certain experience shows us that he hath not (John Locke, Essay Concerning Human Understanding, 1.4.12, emphasis original).

There is a general problem with the epistemology of teleological claims. As Plato (Phaedo 97c ff.) and Leibniz (Discourse on Metaphysics 19-22) both point out, there is something problematic about introducing God and then disavowing teleological explanation. (Plato's target is Anaxagoras; Leibniz's is Descartes.) On the other hand, one of the key points the moderns made against the Scholastics is that if final causal explanations are allowed to run free and are considered adequate explanations of phenomena, empirical investigation will be stopped dead. (Q: Why is the sky blue? A: Because God wanted it that way.) As Locke points out in the above passage, we can even prove falsehoods by this means. For instance:

1. Believing what is false is bad.


2. God does not will anything bad.


3. All and only what God wills occurs.

Therefore,

4. No one ever believes what is false.

Leibniz's approach to carving out a middle ground involves: (1) recognizing that both efficient causal explanation and final causal explanation can be applied to the same phenomena, and we should not be fully satisfied until we have both (this is one form of his famous doctrine of 'pre-established harmony'); (2) distinguishing between the antecedent will of God, which is directed toward things that are good in themselves, and the consequent will of God, which is directed toward the best total state of affairs; and (3) limiting our ability to discover the consequent will of God. According to Leibniz, we have some moral knowledge, so we can often identify genuine goods, and thus items toward which the antecedent will of God is directed. However, the consequent will of God depends on infinitely many considerations - namely, the total history of the actual world, and its comparison with every one of the infinitely many possible worlds. (Leibniz believed that all the good worlds are themselves infinite; by his own lights, were he alive today, he would have to admit, on the basis of empirical discoveries, that he got that one wrong.) So we can only know a tiny fraction of the consequent will of God. We come to know that something is part of God's consequent will by observing it to be actual. Once we observe something to be actual, we may be able to connect it with certain items we know God wills antecedently. This is the project of final causal explanation. According to the view Leibniz expresses in the rather obscure essay Tentanem Anagogicum, final causal explanation, like efficient causal explanation, can proceed by formulating broader and broader generalizations, which can then be empirically confirmed or disconfirmed. An example from after Leibniz's time clearly illustrates the idea: the Principle of Least Action. This principle can be viewed as a precisification of the vague statement "Nature is thrifty in all its actions." As it turns out, precisified in the right way, this statement can be used to derive classical mechanics. Thus the statement is a general principle which is teleological in character and has been empirically confirmed to cover a wide range of phenomena. (Not, however, all phenomena: this is a principle of classical physics, and so makes accurate predictions only when dealing with the distances and energies commonly encountered in everyday life.) In Leibniz's view, we have a vague idea that God, as the great Architect of the universe, would surely (e.g.) follow some sort of efficiency principle, but only empirical investigation can tell us precisely what that principle is.