Introduction

In 1940 R. G. Collingwood published an essay An Essay on Metaphysics that outlines the role of presuppositions and their essential role in questions.

Before we consider presuppositions in questions, it is helpful to define and exemplify their use in sentences.

Definition: The use of a sentence A presupposes B if the truth of B is a necessary condition for A's being successfully used to make a statement capable of being either true or false.

The truth of presupposition B itself is taken for granted.

Examples:

I no longer take the tube to get to work.

It contains the presupposition that I used to take the tube. Further note that presuppositions, unlike entailment, are maintained after negation, i.e.:

I want to go on the tube again. and I don't want to go on the tube again presuppose that you had gone on the tube.

After this short review of presuppositions in sentences, we will move on to Collingwood's work, which defines relative and absolute presuppositions and their role in scientific thinking.

Presupposing

Prop 1: Every statement that anybody ever makes is made in answer to a question.

Def 1.Let that which is stated (i.e. that which can be true or false) be called a proposition, and let stating it be called propounding it.

Collingwood's definition of truth and falsehoods is what can be determined empirically.

Prop 2.Every question involves a presupposition.

For example, the question "Why are you lying?" presupposes that you are lying. Another example is "Which is your favourite movie?" presupposes that you have a favourite movie.

The first part of the pre, as in presupposition refers to logical priority and not a priority in time. Although, in general, a question might have several presuppositions, there is only one primary presupposition.

Def 2. To say that a question 'does not arise' is the ordinary English way of saying that it involves a presupposition which is not in fact being made.

Def 3. The fact that something causes a certain question to arise I call the 'logical efficacy' of that thing.

Def 4. To assume is to suppose by an act of free choice.

Prop 3. The logical efficacy of a supposition does not depend on the truth of what is supposed, or even on its being thought true, but only on it being supposed.

Prop 4. A presupposition is either relative or absolute.

Def 5. By a relative presupposition, I mean one which stands relatively to one question as its presupposition and relatively to another question as its answer.

Def 6. An absolute presupposition is one which stands, relatively to all questions to which it is related, as a presupposition, never as an answer.

Prop 5. Absolute presuppositions are not propositions.

The absolute presuppositions have the property that they constitute the boundary of what could be asked and its extension what could be thought.

By definition 1, absolute presuppositions are not propositions and do not have a truth value. They are instead to be seen as a boundary of what could be asked and, to its extension, what could be thought.

Erotetics: The logical analysis of questions

The first stage of high-grade thinking is to ask questions, knowing that you are asking them.

The second stage is to ask questions with skill or scientifically. The specific skill is the analysis that includes two components: disentangling: The disentangled questions ask only one thing, and arranging, the questions are ordered so that the first question does not depend on the following, the second question depends only on the first, the third on the first and second etc.

Examples

A classic example of logic is the question Have you stopped beating your wife yet?

The original questions contain the presupposition You used to beat your wife. which in turn includes the presupposition You have a wife. In the process of identifying the presuppositions transforming and reordering them, we can form a chain of questions.

Do you have a wife?

Did you use to beat your wife?

Have you stopped beating your wife yet?

With the property that if the answer to the previous question is no, the next question has an unclear meaning.

For example, for a person who doesn't have a wife, the question Did you use to beat your wife? doesn't really make sense, and further, if the answer is yes, should it mean that he has beaten his wife, and if the answer is no, if he hasn't beaten his wife it doesn't make sense to ask whether he has stopped beating her.

The presuppositions, in this case, are propositions, i.e., the presupposition that he has a wife is either true or false, and the presupposition of him having used to beat his wife is also either true or false. It is a relative presupposition as it is also an answer to a question.

Collingwood refers to the process of identifying presuppositions, classifying them, reordering questions as analysis and thinking scientifically. Especially the search for the absolute presuppositions that could be of the nature:

Everything has a cause

The ordinary science collects relative presuppositions, whereas the field of metaphysics contains the absolute presuppositions. The absolute presuppositions do not have any justification and or truth values.