Rationality: From AI to Zombies

by Eliezer Yudkowsky

“Snow” doesn’t have a logical definition known to us—it’s more like an empirically determined pointer to a logical definition. This is true even if you believe that snow is ice crystals is low-temperature tiled water molecules. The water molecules are made of quarks. What if quarks turn out to be made of something else? What is a snowflake, then? You don’t know—but it’s still a snowflake, not a fire hydrant. And of course, these very paragraphs I have just written are likewise far above the level of quarks. “Sensing white stuff, visually categorizing it, and thinking ‘snow’ or ‘not snow’”—this is also talking very far above the quarks. So my meta-beliefs are also promissory notes, for things that an Ideal Omniscient Science Interpreter might know about which configurations of the quarks (or whatever) making up my brain correspond to “believing ‘snow is white.’” But then, the entire grasp that we have upon reality is made up of promissory notes of this kind. So, rather than calling it circular, I prefer to call it self-consistent. This can be a bit unnerving—maintaining a precarious epistemic perch, in both object-level beliefs and reflection, far above a huge unknown underlying fundamental reality, and hoping one doesn’t fall off. On reflection, though, it’s hard to see how things could be any other way.

Anomalous monism + coherentism (Donald Davidson)