His family moved to Belgium in 1925 and it was there that he was first exposed to rhetoric. Perelman's interest in human reasoning came from work he had done on the nature of justice. Since justice involved judgments of value, one could not explain the rationality of these judgments using formal reasoning. Therefore, Perelman was led to construct a new approach that would account for a speaker's practical reasoning. Perelman's view of rhetoric is epistemic.
Speakers come to know through the process of argumentation.
In order to achieve this, a speaker's beliefs and values must gain the adherence of the audience. A Theory of Practical Reasoning. Upon making an argument, a speaker is confronted with a range of possible techniques of presentation that may be used to gain audience adherence. The choice a speaker makes should correspond with the best possible argument that will gain audience agreement. Therefore, choice is epistemic, facilitating how speakers come to know.