68 J.J.C. Smart
systems might be common, those with a planet suitable for the evolution
of intelligent life are extremely rare, and that the prospects of the current
programme SETI (search for extraterrestrial intelligence) are very poor.
This is probably to some extent a temperamental matter, because so much
guesswork and quantifying of probably unquantifiable probabilities is involved,
but I find it hard to believe that we are alone in the universe, or even in our
galaxy. Even if the emergence of intelligent life is rare in the extreme, the
number of galaxies is comparable to the number of stars in our Milky Way
system. The reason I am inclined to believe that there is much other intelli-
gent life in the universe (in which case a lot of it will be very advanced
compared to ourselves) has to do with something like Leslie’s ‘firing squad’
argument (see section 5) being at the back of my mind. Furthermore, the
probability of intelligent life in the total universe of everything that there
is would become a certainty if the universe were infinite or if there were
infinitely many of Carter’s many universes, discussed in section 5.
While not entirely closing our minds to the possibility that we are in fact
alone in the universe let us look at the question of how the existence of life on
other worlds would affect the Christian doctrine of the Trinity. Suppose
(for the sake of argument) that there is an incarnation on ten million other
planets. Does this mean that the Second Person of the Trinity is multiply
incarnated? Or would the Trinity be a (ten million and one)-ity? As far as
I have been able to discover the orthodox view (such as that of E.L. Mascall)
would be to take the former alternative.^109 This is a hard matter which raises
a lot of philosophical problems, but no more so, perhaps, than the original
doctrine of incarnation itself.
The problems that arise from the possibility of life on other worlds does
seem to have been somewhat neglected by theologians. However, recently
John Hick has considered the subject in his book The Metaphor of God
Incarnate, Chapter 9, where he also refers to several other theological writers
who have discussed the matter.^110 Hick’s theory is quite attractive, though
conservative theologians might not like the notion of incarnation to be treated
as metaphorical. A very odd way out was put forward, admittedly in the ima-
ginative context of a fanciful novel, by C.S. Lewis.^111 This was that among
countless other planets containing intelligent life ours is the only one on
which its inhabitants sinned and so needed a Redeemer. One may find some
difficulty in believing that our planet is the only one on which intelligent life
exists, but it is far more difficult to believe that if there are millions of other
planets containing intelligent life, ours is the only one in which sin existed.
Even if intelligent life had existed for millions of years and evolved into
angelically good beings they would have had to pass through the sinful stage
in any evolutionary process that is at the least likely. As was explained on
p. 60, unfortunate tendencies of character (such as combativeness) are likely