Subjectivist and Objectivist interpretations of controversy-based thought

An historical survey and a theoretical analysis of controversy, between dialogue and polemic, from Protagoras to Popper. 1. An historical outline of the two-logoi tradition. 2. The two-logoi fragment: "On every issue there are two arguments opposed to each other". Philological and epistemic questions. 3. From first person singular to first person plural. 4. Concluding remarks: the two-logoi method seems the best available way for prtecting us from subjectivity of prejudice, which disguises itself as pretended objectivity.