October 2022If there were intelligent beings elsewhere in the universe, they'dshare certain truths in common with us. The truths of mathematicswould be the same, because they're true by definition. Ditto forthe truths of physics; the mass of a carbon atom would be the sameon their planet. But I think we'd share other truths with aliensbesides the truths of math and physics, and that it would beworthwhile to think about what these might be.For example, I think we'd share the principle that a controlledexperiment testing some hypothesis entitles us to have proportionallyincreased belief in it. It seems fairly likely, too, that it wouldbe true for aliens that one can get better at something by practicing.We'd probably share Occam's razor. There doesn't seem anythingspecifically human about any of these ideas.We can only guess, of course. We can't say for sure what formsintelligent life might take. Nor is it my goal here to explore thatquestion, interesting though it is. The point of the idea of alientruth is not that it gives us a way to speculate about what formsintelligent life might take, but that it gives us a threshold, ormore precisely a target, for truth. If you're trying to find themost general truths short of those of math or physics, then presumablythey'll be those we'd share in common with other forms of intelligentlife.Alien truth will work best as a heuristic if we err on the side ofgenerosity. If an idea might plausibly be relevant to aliens, that'senough. Justice, for example. I wouldn't want to bet that allintelligent beings would understand the concept of justice, but Iwouldn't want to bet against it either.The idea of alien truth is related to Erdos's idea of God's book.He used to describe a particularly good proof as being in God'sbook, the implication being (a) that a sufficiently good proof wasmore discovered than invented, and (b) that its goodness would beuniversally recognized. If there's such a thing as alien truth,then there's more in God's book than math.What should we call the search for alien truth? The obvious choiceis "philosophy." Whatever else philosophy includes, it shouldprobably include this. I'm fairly sure Aristotle would have thoughtso. One could even make the case that the search for alien truthis, if not an accurate description of philosophy, a gooddefinition for it. I.e. that it's what people who callthemselves philosophers should be doing, whether or not they currentlyare. But I'm not wedded to that; doing it is what matters, not whatwe call it.We may one day have something like alien life among us in the formof AIs. And that may in turn allow us to be precise about whattruths an intelligent being would have to share with us. We mightfind, for example, that it's impossible to create something we'dconsider intelligent that doesn't use Occam's razor. We might oneday even be able to prove that. But though this sort of researchwould be very interesting, it's not necessary for our purposes, oreven the same field; the goal of philosophy, if we're going to call it that, would beto see what ideas we come up with using alien truth as a target,not to say precisely where the threshold of it is. Those two questions might oneday converge, but they'll converge from quite different directions,and till they do, it would be too constraining to restrict ourselvesto thinking only about things we're certain would be alien truths.Especially since this will probably be one of those areas where thebest guesses turn out to be surprisingly close to optimal. (Let'ssee if that one does.)Whatever we call it, the attempt to discover alien truths would bea worthwhile undertaking. And curiously enough, that is itselfprobably an alien truth.Thanks to Trevor Blackwell, Greg Brockman, Patrick Collison, Robert Morris, and Michael Nielsen for reading drafts of this.
