WATER flows on Mars, at least for part of the Martian year. That makes the red planet more habitable than we had thought, but then so probably is one of Saturn’s moons, Enceladus, and one of Jupiter’s, Ganymede. They both seem to harbour vast oceans of liquid water beneath their surfaces.
News that opens up the possibility of life beyond Earth is coming in thick and fast at the moment. Much of it comes from discoveries beyond our solar system, since we have been detecting planets around distant stars since 1992. The tally at the online Extrasolar Planets Encylopaedia stands currently at about 2000.
The figure of 2000 is impressive enough, but the real value of that number comes in helping us to estimate what proportion of all stars have orbiting planets. Even restricting our estimate only to sun-like stars with Earth-like planets, the answer is about two per cent, or about eight billion in our galaxy, the Milky Way, and perhaps 16 billion billion in the observable universe.
Telescopes are now looking at the atmosphere of these planets, searching for tell-tale signs of chemicals associated with life, and theologians are already wondering about the implications of a positive result. Some of that work is sponsored by NASA, which appreciates the place of religion in how people would make sense of such a finding.
SUCH ruminations about extra-terrestrial life are not breaking entirely new ground, however. Popular commentators like to hold up Giordano Bruno (1548-1600) as the pioneer in proposing that the universe is full of life, not least because the public likes a rebel, and Bruno was that — and was burnt at the stake as a result.
Speculation, however, goes further back than Bruno. Nicholas of Cusa (1401-64) was every bit as much an insider as Bruno was an outsider, and he more or less took it for granted that “the regions of the sun and other stars” are in-habited. His Franciscan contemporary Guillaume de Vaurouillon (c.1392-1463) was another significant writer on this topic.
Among post-Reformation Anglicans, John Wilkins (1614-72), a Bishop of Chester and founder of the Royal Society, pondered the significance of life beyond Earth in a volume published in 1684. The title is so long that A Discovery of a New World: or a discourse tending to prove, that ’tis probable there may be another habitable world in the Moon reproduces only about a third of it. Discussions of the Bible, the Fathers, Aquinas, Cusa, contemporary Jesuits, and the pagan writers of antiquity fill every page.
Another priest, John Ray (1627-1705), is sometimes called the father of British natural history. In The Wisdom of God Manifested in the Works of the Creation, he took it as uncontroversial that “Every fix’d star [in number “next to infinite”] . . . is a Sun or Sun-like Body, and in like manner incircled with a Chorus of Planets moving about it. . . [and is] in all likelihood furnished with as great variety of corporeal Creatures, animate and inanimate, as the Earth.”
Unlike any of these thinkers, we now have an empirical basis for these speculations. The locations where life might evolve are enormously widespread — those maybe 16 billion billion Earth-like planets, around Sun-like stars — and the evolution of life is clearly not impossible: we are Exhibit A in that argument. Even without observations of oxygen or other markers of life, the tables seem to have turned in favour of life out there.
THE theological provocations posed by such a thought are many. Questions about Christ will be crucial for Christians, and not least whether to envisage, or expect, incarnations elsewhere. The variety of opinion here is striking. Arthur Peacocke, from a liberal perspective, and Brian Hebblethwaite, from a more conservative one, both conclude that it makes no sense to envisage more than one incarnation.
All the same, while Canon Peacocke assumed that life was probably widespread, and thought that Christian theology would need to revise its account of the incarnation radically as a result, Canon Hebblethwaite thought that theologians who were committed to orthodox Christology had better hope that it was not. For him, “an implication of the Christian incarnation, properly understood, [is] that there are no other intelligent, personal creatures in God’s creation than human beings on earth.”
Others, again Anglican priests, had no problem with multiple incarnations. Eric Mascall was one, on Thomist grounds; as is Canon John Polkinghorne (Features, 9 October), who has written: “If little green men on Mars need saving, then God will take little green flesh.”
There may be only one incarnation, Jesus redeeming only human beings: a hard line on “the salvation of the unevangelised” taken to the ultimate degree. There might be one incarnation, Jesus redeeming universally, across the cosmos, on the basis of his common creaturehood with all life. Or the Word might be multiply incarnate — each Christ redeeming the nature that he takes on. Or maybe not every sentient form of life needs redeeming, as C. S. Lewis explored in his Cosmic Trilogy.
One thing is for certain, though: the exercise of thinking this through breathes fresh life into old Christological discussions.
The Revd Dr Andrew Davison is Starbridge Lecturer in Theology and Natural Sciences in the University of Cambridge, and Canon Philosopher of St Albans Cathedral.