To PERSUADE, To CONVINCE

The contrast or progression, from to persuade to to convince, along with the evolution of audiences from particular to universal, is a major focus of the Treatise on Argumentation (Perelman & Olbrechts-Tyteca [1958]), see persuasion

1. To persuade a particular audience,
to convince the universal audience

Perelman & Olbrechts-Tyteca significantly restructure the concept of audience. First, they extend the concept to written communication, “every speech is addressed to an audience, and it is frequently forgotten that this applies to everything written as well” ([1958] p. 6-7). The focus placed on this expanded concept of audience explains the fact that the Treatise does not engage in the analysis of delivery (pronunciatio), the basic, oral, face-to-face, dimension of classical rhetoric, S. Rhetoric.

The Treatise goes beyond the actual audience to consider the particular audiences and the universal audience. The former is the sole object of classical rhetoric; the latter is a philosophical projection of the essential characters of the former. The notion of audience is then extended to include self-reflection, using the resource of polyphony:

Thus, the nature of the audience to which arguments can be successfully presented will determine to a great extent the direction the arguments will take and the character, the significance that will be attributed to them. What formulation can we make of audiences, which have come to play a normative role, enabling us to judge on the convincing character of an argument? Three kinds of audiences are apparently regarded as enjoying special prerogatives as regards this function, both in current practice and in the view of philosophers. The first such audience consists of the whole of mankind, or at least, of all normal adult person; we shall refer to it as the universal audience. The second consists of the single interlocutor whom a speaker addresses in a dialogue. The third is the subject himself, when he deliberates or gives himself reasons for his actions. (Id., p. 30)

2. A normative opposition

While the translators of classical rhetorical texts use the verbs to persuade or to convince interchangeably, Perelman & Olbrechts-Tyteca distinguish between these two verbs on the basis of the quality of the audience:

We are going to apply the term persuasive to argumentation that only claims validity for a particular audience, and the term convincing to argumentation that presumes to gain the adherence of every rational being. ([1958], p. 28)

This is a stipulative definition, based on a normative perspective. For the New Rhetoric, the norm of argumentation is constituted by the hierarchy of audiences that accept it. This position strongly distinguishes the New Rhetoric from the standard theories of fallacy, for which the norm is given by logical laws, or by a system of rules defining rationality see norms; rules; evaluation.

3. To persuade, to convince: The words

3.1 History

The Greek word for rhetorical proof is pistis. Unlike the scientific and logical word proof, pistis belongs to a family of terms that express the idea of “trust in others; what can be relied upon” and “proof” (Bailly, [Pistis]). The family of Greek terms translated as “persuasion” refers to “obeying”, as well as to “persuading, seducing, deceiving” (id., [Peitho]).
The name of the goddess Peitho, the companion of Aphrodite, sometimes Aphrodite herself, goddess of beauty, seduction and persuasion, also belongs to this family. From this perspective, the word pistis is syncretic; it covers what for us is the field of influence, proof, seduction, submission and persuasion. By definition, rhetorical evidence is persuasive.

The Latin verb suadere means “to advise”; the corresponding adjective, suadus, means “to invite, to insinuate, to persuade” (Gaffiot [1934], Suadeo; Suadus). Persuadere is composed of suadere and the aspectual prefix per-, indicating the completion of the process, meaning: “I. Decide to do something […] II. Persuade, convince” (id., Persuadeo).

Convincere is composed of con- (cum-) “completely” + vincere “to conquer”: “totally conquer” (id., Convinco); its primary meaning is “to confound an adversary” (ibid.). Like per- in persuadere, the prefix cum- refers to a completed action. The same meaning is expressed in to convict, coming from the Latin convictus, past participle of convincere meaning “to refute, to convict” (MW , Convict, Etymology):

1: to find or prove to be guilty. The jury convicted them of fraud.
2: to convince of error or sinfulness

Both persuadere and convincere mark the completion of the action.
According to the grammatical normative tradition, to convince is should be used for situations in which beliefs are changed without action, while to persuade should be used for situations in which action is taken; the rule is based on the etymology of the words. In practice, the two terms are synonymous. The traditional rule is reminiscent of on the rule of redundancy in law (the normative grammarian too is a legal expert), whereby there cannot be two words with the same meaning, as there cannot be two laws to the same effect. However, two words can have the same meaning until everyday usage differentiates them.

3.2 Lexical opposition persuasion vs. conviction

The verbs to persuade and to convince belong to a lexical-semantic field that includes:

This lexical base is a rich source of semantic orientations and oppositions the exploitation of which could contribute to a reflection on the diversity of expected effects of discourse.

To persuade and to convince are equivalent in many contexts.

A tries to persuade / convince B of something
A addresses a persuasive / convincing argument to B
=> then B adopts new persuasions / convictions

However, in other contexts, they are not equivalent:

A letter of persuasion — not *conviction
A considers that B is persuadable (-ible) — not *convince-able

The pair persuader / persuadee is not marched by a pair *convincer / *convincee. Convictive and convict are, at least etymologically, linked to convince. To persuade is not matched by a pair *convincer / *convincee.

The present participle convincing can be used as an independant adjective, meaning “cogent”; a conviction is “a strong belief”. “Very convincing” seems to be more common than “very persuasive”.
Convincing (not persuading) can be used to qualify not only argumentative discourse but also other kinds of discourse:

very convincing accounts, reports…
– – novels, tales, narratives…
– – portraits