Love is the touchstone of virtue.

The saying presents love as a touchstone: a test that reveals whether moral character is genuine. Here, love need not mean romantic feeling; it means caring concern for others. Virtue is not measured only by stated principles or outward correctness.

It also suggests that love gives ethical conduct its deepest value and direction. Actions that appear respectable may be judged incomplete if they lack compassion, goodwill, or sincere regard for another person's welfare, though people may differ on whether love alone is an adequate measure of virtue.

Use this reflective proverb when discussing compassion in personal conduct, service, or ethical judgment. It suits a serious, idealistic context and presents caring concern as a test of authentic virtue, while allowing that standards of virtue may be debated.