The discovery of independent life beyond Earth would have deep philosophical implications for us, and our ideas of morality
Suppose we woke up tomorrow to learn that extraterrestrial life had been discovered. What difference would that make? Set aside the extreme scenarios of popular fiction. The truth will probably be more mundane – not massive spaceships suddenly filling the sky but, instead, microorganisms found deep inside an ice-covered Moon, a non-random radio signal from a distant star system, or the ruins of a long-dead alien civilisation. What difference might those discoveries make? Would they strengthen or weaken our faith in God, or science, or humanity? Would they force us to re-evaluate the importance of our own lives, values and projects?
In academic philosophy today, an interest in extraterrestrial life is regarded with some suspicion. This is a historical anomaly. In Ancient Greece, Epicureans argued that every possible form of life must recur infinitely many times in an infinite universe. In the 17th, 18th and 19th centuries, as modern astronomy demonstrated that our Earth is just another planet and our Sun just another star, the default hypothesis among informed observers was that the Universe is filled with habitable planets and intelligent life. One principal argument for this ‘pluralism’ was philosophical or theological: God (or Nature) does nothing in vain, and therefore such a vast cosmos could not be home to only one small race of rational beings.
My goal here is to explore some unexpected implications of the discovery of extraterrestrial life, and my conclusions are very speculative: extraterrestrial life would lend non-decisive support to several interesting and controversial philosophical positions. The discovery of life elsewhere would teach us that, while the Universe does have a purpose, human beings are irrelevant to that purpose. Aliens might well worship a God who is indifferent to us.
We know that life has emerged once. Why should it be so momentous to learn that it has emerged twice? The reason is that finding life elsewhere would radically change our picture of the Universe. At any point in time, humans will have explored only a tiny fraction of our galaxy, let alone the whole Universe. If life has emerged only once in that small sample, then it is possible that life on Earth is unique. (We might then use anthropic reasoning to explain why we inhabit the Universe’s only inhabited planet: where else could observers find themselves?) But suppose we discover that life has emerged twice within our tiny sample – once on Earth, then again somewhere else. It would follow that life must have emerged a vast number of times across the galaxy. The discovery of independently emerging life would thus teach us that life is ubiquitous. And that discovery could have very significant implications. (The restriction to ‘independently emerging’ life is necessary because life found on meteors, asteroids, Mars or the Moon might have the same origin as life on Earth.)
One perennial set of philosophical questions concerns the nature of values, norms and reasons. Are they objective, universal, mind-independent realities, or merely subjective, relative, mind-dependent human constructions? Normative non-naturalists claim that there are universal, objective, mind-independent facts about value, reason and morality that are not specific to any particular human culture, nor even to human nature in general. Any suitably sophisticated moral agent would perceive the same moral facts and be motivated by them. This strong objectivism is a minority position in contemporary ethics, but one that is gaining respectability – thanks in particular to recent work by the philosophers Thomas Nagel, T M Scanlon and the late Derek Parfit.
Normative non-naturalism combines several distinct claims. Moral statements assert facts; those facts are not reducible to the natural facts discovered by science; and some moral statements are true. When I say that murder is wrong, I claim that murder has the non-natural property of wrongness. If murder is wrong, then it does possess that property.
The normative non-naturalist position is anomalous within a purely naturalist worldview that recognises only the natural facts and properties postulated by science. Secular non-naturalists argue that normative non-naturalism is not as anomalous as it seems, because we already need non-natural facts to explain logic, mathematics or the normativity inherent in good scientific practice itself. Theists argue instead that normative non-naturalism makes much more sense if we already acknowledge a God who transcends the natural world. Either God creates the moral facts along with everything else, or God creates the Universe in response to independently existing normative facts. We will return to the link between theism and non-naturalism.
My central claim is that the discovery that life is ubiquitous would support normative non-naturalism. This is because, if life is ubiquitous, then we need non-naturalism to explain an otherwise puzzling fact. Given the vast number of potentially inhabited planets in the Universe, we would expect at least one extraterrestrial species to have either visited us or transformed the galaxy in ways that were clearly visible. Yet we see no one. Where is everybody? This is the Fermi Paradox, named for the physicist Enrico Fermi who posed the question in 1950.
Continue here….