Full Idea
The bad man is the man who no matter how good he has been is beginning to deteriorate, to grow less good. The good man is the man who no matter how morally unworthy he has been is moving to become better.
Gist of Idea
The good people are those who improve; the bad are those who deteriorate
Source
John Dewey (The Middle Works (15 vols, ed Boydston) [1910], 12:181), quoted by David Hildebrand - Dewey 3 'Reconstruct'
Book Reference
Hildebrand,David: 'Dewey' [One World 2008], p.85
A Reaction
Although a slightly improving rat doesn't sound as good as a slightly deteriorating saint, I have some sympathy with this thought. The desire to improve seems to be right at the heart of what makes good character.