Perelman continously repeats that a fact cannot live autonomously. A fact without the power of reason behind it cannot survive by itself. Rhetoric favours reasonable compromises that are instruments and generators of further evolution. The statement that facts do not speak for themselves has obvious ethical implications. Demonstration employs a formal language or imitates one.
Argumentation uses and is expressly based on human language which is intrinsically ambiguous.
Demonstration is a way of forcing the right conclusion. Argumentation aims for adherence to a certain statement or belief through a rational and reciprocal reasoning process. The New Rhetoric adds new vitality to traditional dialectics. The New Rhetoric is an instrument which can be used to unveil the essence from misleading forms. Perelman makes it clear that argumentation is not bargaining.