As is well-known, the absolutism-relativism debate is concerned with the nature of knowledge, its production and reproduction. Core questions are: is there “some permanent ahistorical matrix or framework to which we can ultimately appeal in determining the nature of rationality, knowledge, truth, reality, goodness or rightness” and how can this framework if present be discerned and reproduced? The problem was reformulated in terms of psychological versus structural validity of analyses. “A psychologically real description of a culture is a description which approximately reproduces in an observer the world of meanings of the native users of that culture. The chapter discusses ethnoscience with respect to this topic, at the same time indirectly addressing the question of what the absolutism-relativism debate can learn from the ethnoscience controversy about psychological versus structural validity. Essentially, ethnoscience is based on some simple assumptions regarding the aim, scope, and method of anthropological research. These presume a specific relationship between language, cognition, and behavior.