From his "Letter Concerning Ethusiasm" in Characteristicks of Men, Manners, Opinions Times:
'Tis not the same with Goodness as with other Qualitys, which we may understand very well, and yet not possess. We may have an excellent Ear in Musick, without being able to perform in any kind. We may judg well of Poetry, without being Poets, or possessing the least of a Poetick Vein: But we can have no tolerable Notion of Goodness, without being tolerably good.
If there is one thing I abhor about how ethics is taught today in universities, and as I experienced it in the classes I took myself, is how ethics is reduced to questions of marginal importance to daily life. Yet how can one possibly reason well about abortion or vegetarianism if one doesn't recognize the good? They're a terrible place to start the discourse! How can we expect people to make tolerable decisions about those issues if they weren't already living virtuous lives?