A fundamentalist preacher from my youth once posed three rules for speech: Is it true? Is it kind? Is it necessary?
This should give us pause from time to time.
Just for the record, the above bromide was brought back to my attention today by Steve Roberts (coolmindwarmheart.com) who attributed it to Eknath Easwaran and an old Arab proverb: The words of the tongue should have three gatekeepers.