For an author to write as he speaks is just as reprehensible as the opposite fault, to speak as he writes; for this gives a pedantic effect to what he says, and at the same time makes him hardly intelligible. Arthur Schopenhauer
Apathy can be overcome by enthusiasm, and enthusiasm can only be aroused by two things: first, an ideal, with takes the imagination by storm, and second, a definite intelligible plan for carrying that ideal into practice. Arnold J. Toynbee
The Athanasian Creed is to me light and intelligible reading in comparison with much that now passes for science. Samuel Butler
That the sun will not rise tomorrow is no less intelligible a proposition, and implies no more contradiction, than the affirmation, that it will rise. David Hume
I believe that history might be, and ought to be, taught in a new fashion so as to make the meaning of it as a process of evolution intelligible to the young. Thomas Huxley