As Daniel Bakken noted here earlier, atheist physicist Lawrence Krauss has responded in The New Yorker to Eric Metaxas’s recent Wall Street Journal essay "Science Increasingly Makes the Case for God." Krauss denies that astrobiology and cosmology point to God’s existence. I disagree with every keystroke of Krauss’s rebuttal, except, oddly, the title: "No, Astrobiology Has Not Made the Case for God." It pains me to agree with Krauss’s assertion, in the following limited sense.

I agree not because I doubt God’s existence, but because saying that science proves it (something that Metaxas himself does not say) would betray a misunderstanding of God’s nature and understates the genuine evidence.

Neither astrobiology nor cosmology, per se, demonstrates God’s existence. God is not demonstrable by the scientific method. God is not a thing in nature, and any scientific argument that claims to demonstrate or disprove his existence is by definition a metaphysical argument, not a scientific one. God is the Ground of Being, not an uncommonly large butterfly that can be pinned to a cork and observed through a microscope.

His existence — his glory and wisdom and love — are manifest in creation, but his manifestation is not the same thing as his demonstration.

There are several strong demonstrations of God’s existence — Aquinas’ Five Ways, the ontological proof, and the argument from moral law, among others. These are logical proofs that depend only minimally on inferences drawn from nature, and do not depend at all on the current state of science.

I’ll expand on one of the proofs — Aquinas’ Fifth Way, which is apropos one of Krauss’s assertions in his article. �

Krauss:

[O]ne of the most severe apparent fine tunings often referred to by creationists like Metaxas is that of the so-called cosmological constant, the energy of empty space that has recently been discovered to be causing the expansion of the universe to accelerate over time. It remains one of the biggest mysteries in physics, as it appears to be over a hundred and twenty orders of magnitude smaller than our theories suggest it could be. And if it were as large as the theories suggest it should be, then galaxies, stars, and planets would never have formed.

Is this a clear example of design? Of course not. If it were zero, which would be "natural" from a theoretical perspective, the universe would in fact be more hospitable to life. If the cosmological constant were different, perhaps vastly different kinds of life might have arisen. Moreover, arguing that God exists because many cosmic mysteries remain is intellectually lazy in the extreme. The more we understand the universe, the more remarkable it appears to be. Exploring how this remarkable diversity can arise by potentially simple laws has been one of the most successful, and intellectually beautiful, efforts in human history.

The cosmological constant is indeed a powerful demonstration of God’s existence. Its power as a demonstration is not in any particular value it takes, but in the fact that it is a constant. The energy of empty space assumes a consistent value, and the universe expands — the universe does not randomly contract and expand and twist and turn and flip upside down every second or two.

The universe behaves in accordance with consistent physical laws. Notice I said consistent — the remarkable thing is not so much that the laws are complex or elegant or specific, but that they are consistent. There is directedness to the universe.

It is the consistent directedness of change in nature — the fact that atoms and rocks and bodies and planets and galaxies and the entire universe have tendencies to do one thing and not another — that leads via reason to the existence of God.

Directedness in nature is teleology. Nature is shot through with teleology, and natural processes cannot be understood without at least implicit reference to teleology.

Aquinas offered a thumbnail sketch of the teleological argument for God’s existence:

The fifth way is taken from the governance of the world. We see that things which lack intelligence, such as natural bodies, act for an end, and this is evident from their acting always, or nearly always, in the same way, so as to obtain the best result. Hence it is plain that not fortuitously, but designedly, do they achieve their end. Now whatever lacks intelligence cannot move towards an end, unless it be directed by some being endowed with knowledge and intelligence; as the arrow is shot to its mark by the archer. Therefore some intelligent being exists by whom all natural things are directed to their end; and this being we call God.

An arrow that consistently hits the target presupposes an archer. The existence in nature of unintelligent things that consistently act to specific ends presupposes an intelligent being who directs their ends.

The argument can be stated:

1. Unintelligent things in nature tend to some outcomes rather than to other outcomes.

2. Tending to specific outcomes entails a kind of foresight, which is a manifestation of intelligence.

3. An Intelligence therefore guides natural outcomes of unintelligent things.

4. This is what all men call God.

The argument is simple, but powerful, and is quite immune to the obfuscation to which atheists habitually resort when complexity and specificity are invoked. Atheists can’t evade the evidence for teleology in the simplest physical processes. One need not understand the intricacies of quantum cosmology. Every drop of rain that drips off Lawrence Krauss’s nose demonstrates God’s existence.

The directedness of natural processes is salient. A single electron orbiting a single proton in accordance with the laws of quantum mechanics is every bit as powerful a demonstration of God’s existence as the whole of cosmology. When you drop a pebble and it falls to the ground, and not to the sky, you demonstrate God’s existence. When you strike a match and you get a flame, and not ice, you demonstrate God’s existence.

Complexity and specificity are just different degrees of directedness. We may look to complex laws of nature to demonstrate God’s existence, but every mundane process at every moment of our lives is a powerful demonstration of it.

When I think of a manifestation of God’s glory, I think of the fine-tuning of the cosmos. When I think of a demonstration of God’s existence, I think of a drop of rain falling to the ground.