Arguments from authority and critical thinking. Side notes toLogic and Argumentation by Andrzej KisielewiczThe article focuses on the role of arguments from authority — or, more precisely, arguments from expert opinion – in rational argumentation and reasoning, in the contemporary context of specialisation of the sciences on the one hand, and the abundance of information on the other. The pretext for this is provided by Andrzej Kisielewicz’s new book: Logika i argumentacja. Praktyczny kurs krytycznego myślenia Logic and Argumentation. A Practical Course In Critical Thinking. I point out that, although Kisielewicz’s book is a valuable contribution to the Polish market of textbooks on argumentation, practical logic and critical thinking, it understates the importance of teaching the ways of proper assessment of arguments from authority, credibility of experts and information sources. I argue that arguments from authority should not be by definition dismissed as fallacies; on the contrary, appealing to authority to expert opinion is an unavoidable element of rational argumentation – at least whenever the discussion requires one to refer to contemporary scientific knowledge. However, relying on experts’ opinions involves genuine risks to the rationality of the debate, many of them having to do with the abundance of pseudoexperts and irresponsibility on the side of some scientists an extensive example is provided by the presentation of statements on GMO’s made by a certain Polish body of scientists. Therefore, the ability to distinguish correct appeals to authority from faulty ones including the ability to tell actual experts from pseudoexperst and reliable sources of information from unreliable ones should be considered a crucial competence which critical thinking courses should teach.