Throughout the second half of the twentieth century, anthropologists failed to elaborate on theoretical concepts such as the 'human condition'. In face of the fact that they did not abandon their scientific calling or the label 'anthropology', this must surely be taken as surprising. The article argues that this silence is possible due to an ideational performance here called the 'all-or-nothing syndrome'. This depends on a skeptical fallacy: the condition of those who, because they cannot have it all, despair of having what is there to be had. The article also explores the Davidsonian notions of 'indeterminacy' and 'underdetermination' as possible paths out of this quandary. It suggests an approach to ethnographic knowledge based on the principles that underscore the mechanisms of control that engineers call 'fuzzy logic'.