The article presents an epistemological analysis of the distinctions between «cognitive distortions», «cognitive biases», and «logical fallacies». The author highlights their differing origins, nature, and roles in cognitive processes. Cognitive distortions are linked to maladaptive beliefs and mental disorders, cognitive biases stem from heuristics under uncertainty, while logical fallacies involve violations of argumentation rules. Drawing on van Lambalgen and Stenning’s works, the study demonstrates that epistemological analysis of cognition must consider not only logical argument structure but also contextual and cognitive factors.