International audience Aristotle appears to favour the use of the word "plèthos" as a prority to "demos" (31/7 occurrences in Politics III). The sentence "kyrion esti to plèthos" appears specifically as a definition of democratic system of government, instead of the usual sentence "kyrion estin o demos". Therefore, must one regard "plèthos" as a political concept, introducing socioeconomic criteria into the definition of democracy? By closely investigating the different uses of "plèthos" in a semantic analysis, we can observe that this word doesn't overstep the limits of its strictly quantitative meaning, as anywhere else