Institutes of the Christian Religion (1559) - John Calvin
Book 2 - God the Redeemer
Chapter 8 - Explanation of the Moral Law:
The 10 Commandments
Sections 47-48 - Ninth Commandment -
Don't Bear False Witness against Your Neighbor
Section 47 - Interpretation: do not lie or deceive.
Slander, maligning one's reputation, backbiting, defamation.
Applies in court, and "in private conversation."
It hurts a man more to take his integrity by slander, than to take his property. But in defaming one, we often end up taking his property, too.
Section 48 - The good reputation of our neighbor
"We delight in a certain poisoned sweetness experienced in ferreting out and in disclosing the evils of others."
This doesn't mean we can't give a just rebuke or civil judgment.
The sin arises from "evil intent and wanton desire to defame."
It is still sin, with this intent, even if the charge is true!
"Eagerness to hear detractions... [and] readiness to make unfavorable judgments, are alike forbidden."