About 25 years ago, a conversation between me and one of the greatest biologists of the 20th century took a weird turn.
I was talking to William D. Hamilton, who was famous for coming up with the theory of “kin selection,” which explains patterns of altruism among close relatives in various species, including ours. This and other seminal ideas had earned Hamilton a place in the pantheon of thinkers who ushered in the modern Darwinian understanding of social behavior. Richard Dawkins, in the preface to his landmark 1976 book,“The Selfish Gene,” paid tribute to Hamilton and the three other “dominant figures” in social biology whose ideas formed the book’s foundation.
I was interviewing Hamilton at the University of Michigan, where he was on sabbatical from Oxford. A video camera was rolling. I had been researching a book about evolutionary psychology, and I was hoping to create a documentary on the subject. The documentary never materialized, and Hamilton died in early 2000. My interview with him sat unwatched until earlier this year, when I tracked down the tape containing it.
During the interview, I was trying to steer Hamilton toward philosophical topics, and at one point he went further than I had expected. He said, “I’m also quite open to the view that there is some kind of ultimate good which is of a religious nature — that we just have to look beyond what the evolutionary theory tells us and accept promptings of what ultimate good is, coming from some other source.” That’s an unusual thing for a great evolutionary biologist to say, but the most unusual part was still to come.
Hamilton continued, in his British accent, “I could enlarge on that in terms of the possible existence of extraterrestrial manipulators who interfere, and so on, but I think this would be getting too far from the general topic of discussion.” Well, maybe, but this sounded at least as interesting as the general topic of discussion. I asked him if he meant that there was some kind of “transcendental purpose” that we humans are generally oblivious to.
He answered: “Yes, yes. There’s one theory of the universe that I rather like — I accept it in an almost joking spirit — and that is that Planet Earth in our solar system is a kind of zoo for extraterrestrial beings who dwell out there somewhere. And this is the best, the most interesting experiment they could set up: to set up the evolution on Planet Earth going in such a way that it would produce these really interesting characters — humans who go around doing things — and they watch their experiment, interfering hardly at all so that almost everything we do comes out according to the laws of nature. But every now and then they see something which doesn’t look quite right — this zoo is going to kill itself off if they let you do this or that.” So, he continued, these extraterrestrials “insert a finger and just change some little thing. And maybe those are the miracles which the religious people like to so emphasize.” He reiterated: “I put it forward in an almost joking spirit. But I think it’s a kind of hypothesis that’s very, very hard to dismiss.”
The headline almost writes itself: “World-Class Scientist Says Miracles Can Happen!” The subhead would add: “Extraterrestrials may play a role.”
But that’s the headline you’d write if you were just trying to maximize clicks. If you wanted to capture the philosophical significance of what Hamilton was saying, you’d take another tack. Rather than focus on miracles, you’d focus on the idea of “higher purpose” — the idea that there’s some point to life on earth that emanates from something that is in some sense beyond it. And — in hopes of generating as many clicks as possible, notwithstanding the philosophical significance — you’d put this in listicle form, laying out several misconceptions that Hamilton had implicitly dispelled. You could call these the “Three Great Myths About Evolution and Purpose.”
Myth number one: To say that there’s in some sense a “higher purpose” means there are “spooky forces” at work.
When I ask scientifically minded people if they think life on earth may have some larger purpose, they typically say no. If I ask them to explain their view, it often turns out that they think that answering yes would mean departing from a scientific worldview — embracing the possibility of supernatural beings or, at the very least, of immaterial factors that lie beyond scientific measurement. But Hamilton’s thought experiment shows that this isn’t necessarily so.
You may consider aliens spooky, but they’re not a spooky force. And they’re not supernatural beings. They’re just physical beings, like us. Their technology is so advanced that their interventions might seem miraculous to us — as various smartphone apps would seem to my great-, great-grandparents — but these interventions would in fact comply with the laws of science.
More to the point: If you ask how Hamilton’s aliens had initially imparted “purpose” to life, the answer is that they did so in concrete fashion: by planting simple self-replicating material on earth a few billion years ago, confident that it would lead to something that would keep them entertained (keeping them entertained being, in this scenario, life’s purpose). Which leads to:
Myth number two: To say that evolution has a purpose is to say that it is driven by something other than natural selection.
The correction of this misconception is in some ways just a corollary of the correction of the first misconception, but it’s worth spelling out: Evolution can have a purpose even if it is a wholly mechanical, material process — that is, even if its sole engine is natural selection. After all, clocks have purposes — to keep time, a purpose imparted by clockmakers — and they’re wholly mechanical. Of course, to suggest that evolution involves the unfolding of some purpose is to suggest that evolution has in some sense been heading somewhere — namely, toward the realization of its purpose. Which leads to:
Myth number three: Evolution couldn’t have a purpose, because it doesn’t have a direction.
The idea that evolution is fundamentally directionless is widespread, in part because one great popularizer of evolution, Stephen Jay Gould, worked hard to leave that impression. As I and others have argued, Gould was at best misleading on this point. And, anyway, even Gould admitted that, yes, on balance evolution tends to create beings of greater and greater complexity. A number of evolutionary biologists would go further and say that evolution was likely, given long enough, to create animals as intelligent as us.
In fact, that idea is implicit in Hamilton’s saying the aliens could have “set up” evolution in such a way that “it would produce these really interesting characters — humans.” This part of Hamilton’s scenario requires no intervention on the part of the aliens, because he believed that evolution by natural selection has a kind of direction in the sense that it is likely, given long enough, to produce very intelligent forms of life. (When speaking more precisely, as he did in other parts of the interview, Hamilton would say that the human species per se wasn’t in the cards — that it wasn’t inevitable that the first intelligent species would look like us.)
With these three myths dispelled, you’re left with this philosophically liberating upshot: You can entertain the possibility that evolution has a purpose, a kind of goal (a “telos,” as philosophers say), without departing from a strictly Darwinian view of evolution — without abandoning belief in natural selection as evolution’s only engine, and without surrendering your credentials as a modern, scientifically minded kind of person.
In case you’re still feeling a little uneasy about becoming a purpose ponderer, I should emphasize that not all teleological scenarios that pass scientific muster involve space aliens. Indeed, some scientists have suggested that natural selection has a purpose that wasn’t instilled by any kind of intelligent being.
This scenario emerges from one version of physicist Lee Smolin’s theory of “cosmological natural selection.” Smolin thinks our universe may itself be a product of a kind of evolution: maybe universes can replicate themselves via black holes, so over time — over a lot of time — you get universes whose physical laws are more and more conducive to replication. (So that’swhy our universe is so good at black-hole making!) In some variants of Smolin’s theory — such as those developed by the late cosmologist Edward Harrison and the mathematician Louis Crane — intelligent beings can play a role in this replication once their technology reaches a point where they can produce black holes. So through cosmological natural selection you’d get universes whose physical properties were more and more conducive to the evolution of intelligent life. This might explain the much-discussed observation that the physical constants of this universe seem “fine-tuned” to permit the emergence of life.
Crane, in a recent dialogue on my website meaningoflife.tv, told me that in this scenario “human life—and I don’t mean on an individual scale, but as a whole—has a purpose in the same sense that a chicken’s egg has a purpose. The purpose of a chicken’s egg is to create a chicken.” Crane isn’t using language carelessly here. Some philosophers are comfortable talking about animals having a “purpose” imbued by natural selection (to spread their genes). So if biological evolution is a product of cosmological natural selection, it has a purpose in a defensible sense of that term—and we’re part of that purpose.
So add another item to our listicle:
Myth number four: If evolution has a purpose, the purpose must have been imbued by an intelligent being.
That said, one interesting feature of current discourse is a growing openness among some scientifically minded people to the possibility that our world has a purpose that was imparted by an intelligent being. I’m referring to “simulation” scenarios, which hold that our seemingly tangible world is actually a kind of projection emanating from some sort of mind-blowingly powerful computer; and the history of our universe, including evolution on this planet, is the unfolding of a computer algorithm whose author must be pretty bright.
You may scoff, but in 2003 the philosopher Nick Bostrom of Oxford University published a paper laying out reasons to think that we are pretty likely to be living in a simulation. And the simulation hypothesis has gained influential supporters. Neil deGrasse Tyson, director of the Hayden Planetarium and America’s de facto astronomer laureate, finds it plausible. The visionary tech entrepreneur Elon Musk says there’s almost no chance that we’re living in “base reality.” The New Yorker reported earlier this year that “two tech billionaires” — it didn’t say whether Musk is one of them — “have gone so far as to secretly engage scientists to work on breaking us out of the simulation.”
I’m guessing that will take awhile, and meanwhile I’d like to note an irony.
When an argument for higher purpose is put this way — that is, when it doesn’t involve the phrase “higher purpose” and, further, is cast more as a technological scenario than a metaphysical one — it is considered intellectually respectable. I don’t mean there aren’t plenty of people who dismiss it. I’m talking about how people dismiss it. The Bostrom paper drew flack, but a lot of it was from people who thought the chances that we’re living in a simulation are way less than 50 percent, not from people who thought the idea was wholly crazy.
If you walked up to the same people who gave Bostrom a respectful hearing and told them there is a transcendent God, many would dismiss the idea out of hand. Yet the simulation hypothesis is a God hypothesis: An intelligence of awe-inspiring power created our universe for reasons we can speculate about but can’t entirely fathom. And, assuming this intelligence still exists, it is in some sense outside of our reality — beyond the reach of our senses — and yet, presumably, it has the power to intervene in our world. Theology has entered “secular” discourse under another name.
Personally, I’m fine with that. I think discussion of higher purpose should be respectable even in a scientific age. I don’t mean I buy the simulation scenario in particular, or the space alien scenario, or the cosmological natural selection scenario. But I do think there’s reason to suspect that there’s some point to this exercise we Earthlings are engaged in, some purpose imbued by something — and that, even if identifying that something is for now hopeless, there are grounds for speculating about what the point of the exercise is.
I won’t elaborate much on this, since I've done that elsewhere, arguing that higher purpose can be framed as a hypothesis, and that evidence for or against the hypothesis can be marshaled. But I will say that the evidence I see for purpose includes not just the direction of biological evolution, but the direction of technological evolution and of the broader social and cultural evolution it drives — the evolution that has carried us from hunter-gatherer bands to the brink of a cohesive global community. And if the purpose involves sustaining this direction — becoming a true global community — then it would seem to include moral progress. In particular, our purpose would involve transcending the psychology of tribalism that can otherwise divide people along ethnic, national, religious and ideological lines. Which would mean — in light of recent political and social developments in the United States and abroad — that our work is cut out for us.
Robert Wright (@robertwrighter) is the author of “The Moral Animal,” “Nonzero” and “The Evolution of God,” and a visiting professor of science and religion at Union Theological Seminary.