Power tends to corrupt and absolute power corrupts absolutely. Great men are almost always bad men.

Lord Acton wrote this line in a private letter during the Victorian-era debates over the moral authority of the Catholic Church and the evaluation of powerful historical figures. In 1887 he corresponded with Bishop Mandell Creighton, who was working on a history of the papacy and had suggested that popes and kings should be judged by different standards than ordinary people. Acton—an English Catholic liberal and historian deeply wary of concentrated authority—rejected that leniency. His remark crystallizes his broader historical method: rulers must be judged by the same moral law as everyone else, and the possession of unchecked power is itself a strong temptation toward wrongdoing.

Acton argues that power is not morally neutral: it creates incentives and opportunities that erode restraint, and the danger increases as accountability decreases. “Absolute power” is especially corrupting because it removes external checks (law, institutions, public scrutiny) and internal checks (humility, fear of consequences). The added sentence—“Great men are almost always bad men”—sharpens the point: the kind of “greatness” celebrated in political history often depends on coercion, conquest, or ruthless decision-making. The quote is less a claim that leadership is inherently evil than a warning that admiration for achievement can become an excuse to forgive abuses committed by the powerful.

1) “Power tends to corrupt, and absolute power corrupts absolutely.”
2) “Power tends to corrupt and absolute power corrupts absolutely. Great men are almost always bad men, even when they exercise influence and not authority.”
3) “Power tends to corrupt; absolute power corrupts absolutely.”