One of the main characteristics of the post-modern society is the democratized diffusion of knowledge even on issues of which the average citizen could hardly be aware: social, cultural, ecological and economical risks. However, many philosophers and thinkers (Chomsky, Barber, Zizek, Sartori) argue that we live rather in information societies than in knowledge ones, because the content of information on political actions of major importance are ideologically-oriented and therefore misleading. In the present paper we study two examples of political and (...) scientific rhetoric, trying to interpret not only their political and moral determinants but also their possible impact on international welfare. Aristotle and modern semiotic theories will provide the methodological tools of thisanalysis. (shrink)