Chaim Perelman

Chaïm Perelman was a Polish-born Belgian philosopher who taught at the Free University of Brussels. Finding formal logic unable to account for reasoning about values, law and practical decisions, he and Lucie Olbrechts-Tyteca studied how arguments actually win adherence. Their 'new rhetoric' treats argumentation as always addressed to an audience, and revived rhetoric as a serious subject for philosophy and legal theory.

Key ideas

• Argumentation aims at the adherence of an audience, not at formal demonstration.
• The 'universal audience' is an argument's idealised standard of reasonableness.
• Reasoning about values and justice is rational even though it is not deductive.
• Legal reasoning is a central model of practical argument.

Major works

• Traité de l'argumentation: La nouvelle rhétorique (1958, with Lucie Olbrechts-Tyteca; The New Rhetoric, 1969)
• L'empire rhétorique (1977; The Realm of Rhetoric)

In the conversation

• Question When Sor Juana protests her own ignorance, is that rhetoric or argument, and does it matter? Valentina Ríos · 4 replies