A presupposition is a background belief (something that sits, unsaid, and helps provide meaning about what a person says). It’s a common term in linguistics. When a person says something (makes an utterance), the meaning of that sentence has to do with the words, etc, but the meaning only exists within the context of what else is in the person’s head that provides meaning.
When two people are trying to communicate, and their presuppositions are not known to each other, that’s when misunderstanding takes place.
Let’s take an example that you’ll be familiar with. Someone says:
Did you stop beating your spouse?
Under what circumstances does that question have meaning? What presuppositions are required for it to make sense and be understood?
It presupposes that “you” have a spouse. It also presupposes that you WERE beating your spouse. The question makes no sense without that supposition, since why would a person ask you if you stopped doing something you were never doing anyway?
The problem in communication is that if one person has a set of presuppositions (you beat your spouse), and the other knows that s/he never beat the spouse, AND, those presuppositions are not placed out in the open, how can you have an intelligent dialogue. Of course, what happens is a nasty argument.
When trying to understand what someone has said, apply Miller’s Law, and dig deeper with questions to surface the person’s presuppositions. When talking, make a conscious effort to put any critical presuppositions you have on the table so they can be discussed.
Linguistically, the reason we have presuppositions is that they are necessary to shorten what we say. If we had to speak every detail underlying what we are trying to say, we’d never say anything. Language is shorthand. Presuppositions allow us to use linguistic shorthand.
