In the various attempts to solve the problem of consistency there is one persistent source of difficulty. It lies in the fact that the axioms are interpreted by models composed of an infinite number of elements. This makes it impossible to encompass the models in a finite number of observations; hence the truth of the axioms themselves is subject to doubt.

— Ernest Nagel, James R. Newman and Douglas R. Hofstadter, Sapiens

PREVIOUS06/17/2020

NEXT06/19/2020