This paper on the methodological problems of measurement in intended to clarify the function of scales in the theory of measurement and to consider the extent to which theoretical results so far achieved provide grounds for a theory of scales. The discussion of this extensive topic, which is of especially great interest for the methodology of measurement in psychology and sociology, will be based on a critical analysis of contemporary literature. This analysis will then allow us to estimate which concepts ought to be rejected and which can be accepted as a starting point for developing a theory of scales that would be at once methodologically sound and fruitful for practical measurement.