You may depend upon it that he is a good man whose intimate friends are all good.

Close friendships are chosen twice, once by you and once by them, which makes a whole circle of decent people fairly strong evidence. Anyone can have one respectable acquaintance by accident; having no close friend you would be uneasy to introduce takes consistent taste over years. The reverse is worth noticing too, gently, since people tend to keep the company that does not challenge them.

Picture introducing your closest friends to somebody whose judgment you respect, one at a time. If you flinch at any of them, ask what you have been tolerating, and what it has cost you already.