Thucydides,
History of the Peloponnesian War…
“ The truth is that great good fortune coming suddenly and unexpectedly tends to make a people insolent; in most cases it is safer for mankind to have success in reason than out of reason; and it is easier for them, one may say, to stave off adversity than to preserve prosperity. Our mistake has been to distinguish the Mitylenians as we have done: had they been long ago treated like the rest, they never would have so far forgotten themselves, human nature being as surely made arrogant by consideration as it is awed by firmness. ”
