# Full Logic

## ↑ 4 References

“(I digress here to remark that the symmetry of the expression for the mutual information shows that Y must tell us as much about Z, on average, as Z tells us about Y. I leave it as an exercise to the reader to reconcile this with anything they were taught in logic class about how, if all ravens are black, being allowed to reason Raven(x) ⇒ Black(x) doesn’t mean you’re allowed to reason Black(x) ⇒ Raven(x). How different seem the symmetrical probability flows of the Bayesian, from the sharp lurches of logic—even though the latter is just a degenerate case of the former.)” (Eliezer Yudkowsky, Rationality)

^27ecf7

This is an example of Full Logic, and Evidence is symmetric

(One can get into Deductive thinking here, since Words are pointers to concept-space and if one believes that the Concept-space for “thoughts” and the set of all things I think are the exact same, or something like that. If we realize we are only thinking deductively, then it likely will serve us to Focus on outcomes not definitions.)