Franklin offers practical advice about attentiveness in conversation. Looking at another person’s eyes while speaking can help a speaker judge whether they are engaged, doubtful or affected by what is being said. Watching the mouth while listening directs attention towards the words themselves and may also make speech easier to follow.

The saying reflects an older style of advice about social conduct rather than a strict rule for modern communication. Eye contact, facial expression and other cues vary between individuals and cultures, and people do not all communicate in the same way. Franklin’s broader point is that conversation requires active observation as well as speech. Effective communication depends not only on expressing oneself clearly, but also on paying close attention when another person is speaking.