A thing moderately good is not so good as it ought to be. Moderation in temper is always a virtue; but moderation in principle is always a vice.

Paine draws a sharp distinction between personal disposition and moral or political commitment. He concedes that moderation of temperament—self-control, patience, and restraint in one’s manner—is admirable. But he argues that “moderation in principle” (compromising on core truths such as justice, liberty, or rights) is not prudence but moral failure. The opening sentence reinforces this: something only “moderately good” falls short of what duty requires. The quote reflects Paine’s broader revolutionary polemic against half-measures and conciliatory politics when fundamental principles are at stake, insisting that ethical clarity should not be diluted for the sake of comfort or expediency.