•  Some significant fraction of the knowledge that a robust system is likely to be 

causal, and to support counterfactuals.  Sophisticated people don’t, for example, just 
know that states have capitals, they know that those capitals are determined, 
politically, by the actions of people, and that those decisions can occasionally be 
changed. Albany is the present capital of New York State, but if the capital were 
(counterfactually) burned to the ground, we recognize that the state might choose a 
new capital.  Children know that when glass bottles drop against hard floors, those 
bottles may break. 

•  Although it is relatively easy to scrape the web for factual knowledge, such as
The Next Decade in AI-