Mortimer Adler’s advice for good conversation.
Stick to the issue. Stay within the framework of the subject under consideration, either as a whole or with respect to one or another of its parts. Don’t wander off and talk about something else or intrude irrelevancies into the course of the conversation.
In short, be relevant, first, last, and always. I wish I could write out a prescription for being relevant. It would provide the remedy for so many of the ills that beset our talking with one another. Being relevant simply consists in paying close attention to the point that is being talked about and saying nothing that is not significantly related to it.
How to Speak, How to Listen, page 150
This is another way of calling for careful definitions, and which of us has not been speaking with a friend (or adversary) only to be amused, frustrated, or dismayed that they were not able to keep to the point? Jesus always stayed on the right point, and thus was always relevant. His followers should follow Him even in this.