From a Letter of January 8th, 1750.

YOUR moral character must be not only pure, but, like Cæsar’s wife, unsuspected. The least speck or blemish upon it is fatal. Nothing degrades and vilifies more, for it excites and unites detestation and contempt. There are, however, wretches in the world profligate enough to explode all notions of moral good and evil; to maintain that they are merely local, and depend entirely upon the customs and fashions of different countries: nay, there are still, if possible, more unaccountable wretches; I mean those who affect to preach and propagate such absurd and infamous notions, without believing them themselves. These are the devil’s hypocrites. Avoid, as much as possible, the company of such people, who reflect a degree of discredit and infamy upon all who converse with them. But as you may, sometimes, by accident, fall into such company, take great care that no complaisance, no good humor, no warmth of festal mirth, ever make you seem even to acquiesce, much less to approve or applaud, such infamous doctrines. On the other hand, do not debate, nor enter into serious argument upon a subject so much below it; but content yourself with telling these apostles that you know they are not serious; that you have a much better opinion of them than they would have you have; and that you are very sure they would not practice the doctrine they preach. But put your private mark upon them, and shun them for ever afterwards.