a) that we can anticipate benefits and fear of their consequences, eg. speaking against one person to help another.
b) that we anticipate damage but no benefit at all, such as profanity and tale bearing.
c) that we can anticipate neither damage nor benefits, such as telling what happened, news in the time of war.
d) that we can anticipate only benefit and no damage at all eg. re: wisdom and about good character. He advocates that we limit speech to the fourth category.