Gibbon, not the monkey...

"The decline of Rome was the natural and inevitable effect of immoderate greatness. Prosperity ripened the principle of decay; the cause of the destruction multiplied with the extent of conquest; and, as soon as time or accident removed the artificial supports, the stupendous fabric yielded to the pressure of its own weight. The story of the ruin is simple and obvious: and instead of inquiring why the Roman Empire was destroyed we should rather be surprised that it subsisted for so long."

Gibbon, Decline and Fall of the Roman Empire, 2nd ed., vol. 4,