(from the Greek paralogos – contrary to reason, unreasonable; “crooked logic”) is a disorder of thinking characterized by a violation of logical connections. There are logical errors in thinking due to the one-sidedness and tendentiousness of the patient’s thinking, which lead him to conclusions that contradict reality. Logical errors lie in incorrectly used premises and evidence, incorrectly constructed cause-and-effect relationships, confusion of concepts, etc. In this case, intellectual and mnestic abilities are preserved, and patients are able to reason correctly beyond the boundaries of their delusional plot.