A good argument is like a piece of technology. Few of us will ever invent a new piece of technology, and on any given day it’s unlikely that we’ll adopt one. Nevertheless, the world we inhabit is defined by technological change. Likewise, I believe that the world we inhabit is a product of good moral arguments. It’s hard to catch someone in the midst of reasoned moral persuasion, and harder still to observe the genesis of a good argument. But I believe that without our capacity for moral reasoning, the world would be a very different place.

-Joshua Greene, “Moral Tribes”, Endnotes