The Ethics of Infinity

If the universe is infinite, containing infinitely many beings, how should this affect our moral reasoning? The mathematics of infinity poses strange challenges to utilitarian thinking.

Classical utilitarianism tells us to maximize total happiness. But in an infinite universe, the total might already be infinite—or undefined. Adding any finite amount of good seems to make no difference to an infinite sum. This is sometimes called the "infinitarian paralysis."

Some philosophers respond by retreating to local concerns: we can only affect beings near us, so focus there. But this seems arbitrary. If we could affect distant beings, shouldn't we? And in principle, with enough technology, perhaps we could.

The mathematician Georg Cantor showed that not all infinities are equal. Perhaps some infinite outcomes are genuinely better than others, even if we can't compare them by simple addition. Developing an ethical calculus for infinite stakes remains an open problem at the intersection of mathematics and moral philosophy.

What's certain is that our intuitions about ethics were forged in a world that seemed finite. As our cosmological knowledge expands, our ethics may need to expand with it.