Note three aphorisms that deal directly with friendship.

This question is referring to the aphorisms Franklin published under the pseudonym "Poor Richard." The first aphorism is "the wise man draws more advantage from his enemies than the fool from his friends." This aphorism essentially means that wise men pay attention to what their enemies say about them and how they act against them. Your enemies are looking for your weaknesses and shortcomings. They have no interest in portraying you in a positive light. Your friends might flatter you, and, while it is important to have friends, they cannot really teach you anything. Another aphorism is "when befriended, remember it; when you befriend, forget it." In this context, "friend" seems to mean something like "benefactor" rather than "companion." Essentially, when someone does something for you, remember it, so you can reciprocate. When you do something good for someone else, do not expect anything in return. Do good things for people, in other words, for the sake of doing good. Finally, "hear no ill of a friend, nor speak any of an enemy" is more or less self-explanatory. It means that one should defend one's friends if others are speaking ill of them and that one should not say bad things about even their enemies.