“What would convince me that 2 + 2 = 3, in other words, is exactly the same kind of evidence that currently convinces me that 2 + 2 = 4: The evidential crossfire of physical observation, mental visualization, and social agreement.” (Eliezer Yudkowsky, Rationality)

^3c3d73

The “crossfire” is an interesting one. What are we convinced by?