There never was a truly great man that was not at the same time truly virtuous.

Greatness measured only by output is a thin measure, and history keeps supplying examples of impressive people it would have been terrible to know. Insisting that character belongs in the definition is a way of refusing to let achievement buy an exemption. Whether it is literally true is arguable; as a standard to apply, it is a good one.

Apply it to whoever you currently admire, and to yourself. Ask how the person behaved toward those who could do nothing for them. That single question sorts reputations faster than any account of what they accomplished.