Values, scales, and the existence of properties

This chapter aims to expand on the ontological and epistemological analysis of properties introduced in the previous chapter, with a discussion of three fundamental issues for measurement science. Restarting from the distinction between general and individual properties, the first is about the nature of values of quantities and more generally of properties, thus allowing us to further discuss the epistemic role of Basic Evaluation Equations. The second issue relates to the classification of properties, or of property evaluations, in terms of scale types, and thus particularly to the characterization of quantities as specific kinds of properties, thus leading to the question of whether, and under what conditions, nonquantitative properties can be measured. On this basis, the third problem is explored: the conditions of existence of general properties and the role of measurement in the definition of general properties.