PRESUPPOSITION
The concept of presupposition can be approached as a logical or as a linguistic problem.
1. A logical problem
The problem of presupposition was first addressed in the field of logic, see Proposition The logic of analyzed propositions postulates that propositions such as “all As are Bs” can have two truth values, the true and the false. The problem arises when the reference of A and/or B is null (there is neither A nor B), as in “unicorns can fly (are flying creatures)” or “no unicorn is a dragon”. In such a case, is the proposition “all As are Bs” true or false? Consider the proposition “The king of France is bald”, said in 1905. It is impossible to assign a truth value to this statement, since in 1905, and still today, the French Republic does not have a king (Russell 1905).
From the point of view of logical technique, it is sufficient to add the premises “there are As”, and “there are Bs”, or “there is one, and only one king of France”. An apparently mono-propositional statement such as “the king of France is bald” is then translated into logical language by the conjunction of three propositions, each of which has its own truth value:
“there is a king of France” & “there is only one king of France” & “he is bald”.
In 1905 as now, the first of the three propositions is false. It follows that the conjunction of logical propositions representing the statement “the king of France is bald” is simply false. This analysis has been criticized for failing to reflect the linguistic intuition of the ordinary speaker, for whom the statements “there is a king of France” and “this king is bald” do not have the same status in the original sentence: the first is asserted, the second is presupposed. This is true, but the objection is irrelevant, since formal logic does not aim to represent linguistic intuition, but wants to solve a technical problem, and this is what it does.
2. A linguistic problem
Ordinary statements can articulate different judgments, which have different semantic and discursive statuses, as is clearly shown in the case of statements presupposing another statement
Imposing a presuppositional judgment violates the logical principle that a proposition expresses a single judgment (if it contains multiple judgments, each must be asserted separately). Therefore, it violates the dialectical rule that each proposition must be explicitly accepted or rejected by the respondent. Thus, S1 could therefore ask S2 « why P? » only if S1 and S2 had previously agreed on the existence of P. From a Perelmanian perspective, the question of presuppositions should be settled within the framework of prior agreements, S. Conditions for discussion.
2.1 The layered structure of meaning
The presupposition is defined as an element of the semantic content of the utterance that resists negation and interrogation. The statement “Peter no longer smokes” presupposes that “Peter used to smoke”, and posits that “Peter no longer smokes”. The negative statement “Peter has not stopped smoking” and the interrogative “Has Peter stopped smoking?” share this presupposed content, “Peter used to smoke”. Negation and interrogation deal with the posed content (“Peter smokes now”), and do not change the presupposed content.
This layered structure of sentences is one of the main features that distinguishes statements made in ordinary language from logical propositions.
2.2 Presupposition as a speech act and the “many questions” problem
Ducrot redefines presupposition as a strategic act (an illocutionary act) performed with the aim of influencing, i.e. restricting the interlocutor’s possibilities to speak. The act of presupposition is a discursive power grab by which the speaker performs
An act of legal value [1], and thus an illocutionary act […] This act] transforms the interlocutor’s possibilities of speech, […] It modifies the interlocutor’s right to speak” (1972, p. 91).
Consider the following question:
Interviewer — What are you going to do to fight corruption in your own party?
The question assumes that “there are corrupt people and practices in your party”. The respondent is given a choice:
(i) Either he or she accepts the presupposed statement and gives a response within the range of pre-formatted, expected responses, such as:
Respondent — I’m going to suspend all the members under investigation.
This answer respects the linguistic orientation of the question. It falls perfectly within the framework of the dialog as established by the first speaker. The respondent submits to the interviewer.
(ii) He could also deny the presupposed statement:
Interviewee — To my knowledge, there is no (proven) case of corruption within my party
This second response reframes the routine consensual dialogue; the interviewee rejects the claim made by the interviewer, and the dialogue takes on an uncompromising and polemical character, opening an argumentative2 situation structured by the question “are there (proven) cases of corruption in the party?” The rejection of the assumption
“[is] always considered aggressive: it personalizes the debate, which becomes a quarrel. […] To attack the opponent’s presupposition is to attack the opponent himself” (Ducrot 1972, p. 92).
The presupposition seeks to impose an “ideological framework” (ibid., p. 97) on the ensuing dialog, that is, to direct the partner’s speech. S. Many Questions; Conditions of Discussion; Persuasion.
Of course, the phenomena of presuppositions are not limited to dialogue, but, as always, dialogue serves to clarify the problem. A monologue that did not respect its own presuppositions would be inconsistent, while, in dialogue, the rejection of a presupposition is controversial. In reality, dialog (i) develops under the same conditions as a monologue.
The case of presupposition is by no means the only content that can be exploited by a multiple question. In ordinary language all statements are more or less « loaded » not only by their orientation, but also by their implicit contents of various kinds, some of which are derived from the orientation of words. In reality, it is always possible to extract contentious implicit judgments or to infer propositional judements from a statement and to hold the interlocutor responsible for them; any proposal is loaded with its consequence.
Consider a conversation between a banker and a customer who is trying to get a better interest rate:
S1_1: – I went to the bank opposite my house and they immediately offered me a loan at a lower rate than the one you propose me!
S2: – That’s because they wanted you as a customer.
S1_2: – Because you do not want to keep me as a customer?
S1_2 extracts or infers from S2’s intervention an implicit content that S2 certainly rejects, but nevertheless shows the banker that more explanations are needed. This move can be seen as a special straw man maneuver (de Saussure 2015).
[1] Based on a valid linguistic convention.