Final answer:
This aphorism by Franklin emphasizes the importance of judging people's actions on a case-by-case basis.
Step-by-step explanation:
This aphorism by Franklin means that if a person is not acting correctly in one situation, don't assume that she will act correctly in another.
For example, if someone consistently lies to avoid punishment, it is unwise to trust them to be honest in a different situation. This quote emphasizes the importance of judging people's actions on a case-by-case basis, rather than assuming consistent behavior.