Concepts contain causal hypotheses, so theories are already two-level

Evidence

As this volume has stressed throughout, secondary-level dimensions play a key causal part in the larger theoretical, explanatory enterprise. If one takes the standard regression-type model it consists of basic-level concepts. Once we put multilevel concepts into these variables we produce multilevel theories. As a result, we will refer to two-level theories. We call them twoand not three-level theories because the third level of concepts deals with measurement and data. This level rarely comes into play in the description of causal mechanisms and explanations at the basic level. In contrast, secondary-level dimensions frequently appear as part of the theoretical framework. — Gary Goertz, Social Science Concepts, 1568

Categorization

• DEFINE: Defines ‘two-level theory’: basic-level variables plus secondary-level dimensions, with measurement as a separate third level excluded from causal description.
• XREF: Connects to the book’s earlier ontology/substitutability framework and to the positivist dispute literature on theory-laden measurement.