Natural theology, after the invoice arrives

From Fine-Tuning to Christianity

Fine-tuning may open a metaphysical question. It does not close a theological case.

City of Dis essay | Philosophy of religion | Cosmicism

Fine-tuning is one of the more respectable arguments in the apologetic armoury, which is why it is so often handled as badly as possible.

The serious version is not "the universe looks pretty, therefore Jesus". Nor is it the charmingly hopeless social-media version in which someone discovers that stars exist and immediately starts reciting John 3:16 as if cosmology has been caught wearing a clerical collar. The serious claim is narrower and more interesting: certain physical constants, boundary conditions, and cosmological features appear to fall within ranges that allow complex chemistry, long-lived stars, stable matter, and eventually life. Had they been significantly different, the universe might have contained no observers, no biology, no chemistry worth speaking of, perhaps not even durable structure.

That is a real philosophical problem. It deserves better than being used as a theological trebuchet.

The first step in the argument is usually this: the life-permitting structure of the universe seems surprising under brute chance. If there is only one universe, and if its constants could have varied, and if the range permitting life is narrow, then the existence of a life-permitting universe calls for explanation. That explanation, the apologist says, is not blind luck. It is design.

So far, let us be generous. Let us grant the largest version of the argument. Let us suppose the universe really is fine-tuned. Let us suppose the multiverse is unavailable, speculative, inflated, ugly, or otherwise too metaphysically expensive for the apologist's taste. Let us suppose physical necessity cannot explain the constants. Let us suppose, for the sake of argument, that "design" is a live explanation.

Even then, Christianity has not yet entered the room. It is still in the car park, polishing its shoes.

Fine-tuning, at most, might suggest some kind of ordering intelligence behind the cosmos. It does not tell us that this intelligence is omnipotent, omniscient, morally perfect, providential, personal, loving, triune, incarnate, covenant-making, prayer-answering, sin-forgiving, sacrament-authorising, Bible-inspiring, or especially interested in first-century Palestine. Those are not small details. They are the actual content of Christianity.

The journey from fine-tuning to Christianity therefore requires several additional bridges. Each one has to be built. None may be smuggled in under cover of the word "God".

The first bridge: from fine-tuning to intelligence

Perhaps the universe is arranged by mind. But what kind of mind? A cosmic engineer? A committee of designers? A demiurge? A simulator? A morally indifferent architect? A dying civilisation running ancestral experiments? A Platonic ordering principle? A necessary intelligence with no interest in worship? A universe-generating mechanism whose products include life-permitting regions by selection effect? The design inference, even if accepted, does not specify the designer.

This is where apologetics often performs its first little conjuring trick. The argument begins with "some explanation for physical constants" and ends with "my God". But "my God" contains an enormous amount of theological cargo. The argument has not earned it. Fine-tuning gives you, at most, a silhouette. Christianity supplies a biography, psychology, moral character, historical plan, chosen texts, rituals, ecclesiology, and eschatology. A silhouette is not a passport.

The second bridge: from intelligence to theism

A designer of this universe need not be the classical God of Christianity. Classical theism speaks of a necessary, simple, eternal, omnipotent, omniscient, perfectly good creator who is not merely one powerful being among others. Fine-tuning does not obviously get you there. It may suggest power, but not omnipotence. It may suggest knowledge, but not omniscience. It may suggest intention, but not perfect goodness. It may suggest a cause of this cosmos, but not the necessary ground of all being.

Indeed, the universe itself is an awkward exhibit for the moral character of its alleged designer. The same physical order that permits life also produces extinction, cancer, parasitism, predation, congenital suffering, asteroid impacts, radiation damage, famine, tectonic catastrophe, and deep time soaked in biological agony long before any human moral drama appeared. A life-permitting universe is not the same thing as a benevolent nursery. It is also a death-permitting universe, a waste-permitting universe, a universe in which almost everything is lethal, empty, frozen, incandescent, irradiated, or otherwise magnificently indifferent to mammals with theological opinions.

The remaining bridges

The third bridge is from theism to monotheism. Fine-tuning does not by itself exclude polytheism, henotheism, dualism, emanationism, deism, pantheism, panentheism, or various forms of philosophical idealism. If one is going to say "the constants point to one God", one must argue for the one. It will not do to pretend that theism and Christianity are the same destination with different parking arrangements.

The fourth bridge is from monotheism to biblical religion. Even if one arrived at a single creator, why Judaism, Christianity, or Islam rather than some philosophical theism? Why revelation at all? Why scripture? Why prophets? Why covenant? Why sin? Why redemption? Fine-tuning says nothing about Abraham, Moses, Sinai, Israel, the prophets, or the long theological history out of which Christianity emerges. The constants of physics do not contain footnotes to Deuteronomy.

The fifth bridge is from biblical religion to Christianity. Here the argument must leave cosmology almost entirely and enter history, textual criticism, theology, and comparative religion. Christianity depends on claims about Jesus of Nazareth: his life, teaching, crucifixion, resurrection, divine status, and relation to Israel's God. None of that follows from the cosmological constant. The gravitational constant does not whisper the Nicene Creed. The electron-to-proton mass ratio does not adjudicate Chalcedon. The strong nuclear force does not tell us whether the Gospel of John preserves high Christology because it is true, developed, liturgical, theological, or all of the above.

At this point the Christian apologist needs an entirely different argument. Perhaps an argument from the resurrection. Perhaps an argument from religious experience. Perhaps an argument from fulfilled prophecy. Perhaps an argument from moral transformation, ecclesial continuity, apostolic testimony, or the coherence of Christian metaphysics. Some of these arguments are more interesting than others. Some are frankly anaemic. But they are not the fine-tuning argument. They are additional arguments, and they must be defended on their own merits.

The ladder actually required

There is a possible route, then, from fine-tuning to Christianity. It looks something like this:

That is the ladder. It is not absurd in structure. It is not even necessarily stupid. But it is long, fragile, and frequently misrepresented by people who have only climbed the first rung and are already waving from the steeple.

The weak point is not merely that each step can be disputed. The weak point is that each step introduces new information not contained in the previous one. Fine-tuning does not naturally unfold into the Trinity. It does not entail incarnation. It does not entail atonement. It does not entail original sin. It does not entail eternal judgement. It does not entail the authority of bishops, pastors, popes, councils, confessions, or whichever YouTube apologist has most recently discovered the word "contingency".

Christianity may try to incorporate fine-tuning into a wider natural theology. That is perfectly legitimate. A Christian may say: "Given my prior belief in God, fine-tuning is what I would expect." That is a modest claim. It says fine-tuning fits Christianity. It does not say fine-tuning proves Christianity.

The distinction matters. Many things can be made to fit a worldview after the fact. A Muslim may interpret fine-tuning as evidence of Allah's creative wisdom. A Jew may interpret it as consonant with creation by the God of Israel. A deist may take it as evidence of a rational cosmic architect who never inspired a single gospel. A Platonist may see mathematical order. A simulation theorist may see parameter selection. A cosmicist may see the bleak comedy of a universe in which life is possible but plainly not central.

The Christian must therefore show not merely that Christianity can accommodate fine-tuning, but that Christianity explains it better than its rivals. That is a much harder task. It requires comparative theology, philosophy of religion, metaphysics, history, and probability. It is not accomplished by pointing at stars and saying "checkmate".

Life-permitting is not purpose-proving

There is also a deeper problem. Fine-tuning arguments often rely on the fact that life is possible. Christianity, however, usually wants more than possibility. It wants purpose. It wants human beings to be intended. It wants the cosmos to be, in some sense, a theatre for divine-human drama. Creation, fall, incarnation, redemption, judgement, and eternal destiny are not minor decorative elements. They make humanity spiritually central. Yet the actual universe looks extravagantly non-human in scale, age, structure, and indifference.

This does not disprove Christianity. The universe is under no obligation to look the way atheists prefer. But it does make the apologetic move less tidy than advertised. If the universe is designed for human beings, it is designed with an astonishing taste for delay, waste, extinction, distance, silence, and lethal surplus. The observable cosmos contains hundreds of billions of galaxies. Earth appears very late. Life spends most of its history without us. Human civilisation occupies a microscopic instant. The overwhelming majority of the universe is not merely uninhabited by us, but hostile to us.

One may say, of course, that God has reasons. The apologist always has that card. It is small, laminated, and apparently indestructible. But once one starts relying heavily on unknown divine reasons, the fine-tuning argument loses some of its advertised clarity. The argument begins by saying the universe's structure is intelligible evidence of divine purpose. It then retreats, when the structure looks morally or anthropocentrically awkward, into the claim that divine purpose may be inscrutable. That is not necessarily incoherent, but it is certainly convenient. One should not sell the universe as obvious evidence when it flatters the doctrine and inscrutable mystery when it embarrasses it.

The adult version of the argument

The most honest Christian route from fine-tuning to Christianity would be cumulative rather than triumphalist. It would say something like this:

Fine-tuning may make some form of theism more plausible. Classical metaphysics may then refine that theism into belief in a necessary creator. Moral and religious arguments may suggest that this creator is personal and good. Historical arguments concerning Israel, Jesus, and the resurrection may then identify that creator with the God disclosed in Christianity. Therefore, fine-tuning is not a proof of Christianity, but one strand in a larger cumulative case.

That is at least intellectually adult. It admits the intervening work. It does not pretend that cosmology has secretly done the job of New Testament studies.

The cosmicist reply is equally simple. Even if the universe is fine-tuned, that does not mean it is tuned for us in any comforting sense. A universe can permit life without caring about it. A structure can be mathematically elegant without being paternal. A cosmos can be intelligible without being benevolent. The stars may be lawful without being liturgical.

Fine-tuning may open a metaphysical question. It does not close a theological case.

So, how does one get from fine-tuning to Christianity?

Slowly. With difficulty. By adding argument after argument, each one more specific and more vulnerable than the last. One must move from physics to metaphysics, from metaphysics to theism, from theism to monotheism, from monotheism to revelation, from revelation to Israel, from Israel to Jesus, from Jesus to resurrection, from resurrection to doctrine, from doctrine to church, and from church to whatever version of Christianity one happens to be defending this week.

That journey may be attempted. It may even be argued with sophistication. But it cannot be honestly compressed into "fine-tuning, therefore Christianity". That is not an argument. It is a theological customs fraud, sneaking a cathedral through the border in a suitcase labelled "constants".