This document introduces the concept of "functional stupidity" to describe how organizations rely not just on intelligence but also the denial of cognitive abilities. The authors argue that functional stupidity, defined as a lack of reflexivity, substantive reasoning and justification, can facilitate organizational functioning by providing certainty. However, it can also trap organizations in problematic patterns of thinking. The authors develop a model of functional stupidity and how it arises from contexts dominated by image and symbolic manipulation, and is reinforced through "stupidity management" that represses doubt.