It’s said that “power corrupts,” but actually it’s more true that power attracts the corruptible. The sane are usually attracted by other things than power. When they do act, they think of it as service, which has limits. The tyrant, though, seeks mastery, for which he is insatiable, implacable.

David Brin (b. 1950) American scientist and author

The Postman, ch. 14 (1985)

Often paraphrased: "It is said that power corrupts, but actually it's more true that power attracts the corruptible. The sane are usually attracted by other things than power." See Frank Herbert.