I ask myself, have nations ever declined from a loss of moral sense rather than from physical reasons or the pressure of barbarians? I think that they have.

The poets have familiarized more people with history than have the historians.

Reasonable orders are easy enough to obey; it is capricious, bureaucratic or plain idiotic demands that form the habit of discipline.

Books are humanity in print.

One must stop conducting research before one has finished. Otherwise, one will never stop and never finish.

The appetite for power is old and irrepressible in humankind, and in its action almost always destructive.

To a historian libraries are food, shelter, and even muse. They are of two kinds: the library of published material, books, pamphlets, periodicals, and the archive of unpublished papers and documents.