Arthur Eddington Quote

Nowadays whenever enthusiasts meet together to discuss theoretical physics the talk sooner or later turns in a certain direction. You leave them conversing on their special problems or the latest discoveries; but return after an hour and it is any odds that they will have reached an allengrossing topic - the desperate state of their ignorance.

The Nature of the Physical World, Chapter IX (p. 179), D. Appleton & Co. 1900