On the Use of ‘Explanatory Power’ in Syntactic Research

In much of contemporary syntactic research, the term “explanatory power” is used rather liberally, often to praise a theory’s ability to “account for” a set of observations or unify descriptive generalizations. However, such usage rarely involves a formally explicit deductive system, let alone one that generates disconfirmable predictions. In the absence of these features, “explanatory power” functions as a rhetorically suggestive label, not a claim justified by clearly defined hypotheses, disconfirmable predictions, and experimental results in support of the predictions.

By contrast, within Language Faculty Science (LFS), explanatory power would be reserved, if the term were used, for theories that:

• Operate with a minimal set of formal primitives (e.g., Merge),
• Yield deduced predictions under rigorously constrained conditions,
• And undergo systematic testing for disconfirmation based on individual speaker judgments.

Without these elements—formal precision, predictive deductiveness, and empirical testability—the appeal to explanatory power becomes an artifact of professional rhetoric rather than a property of scientific inference. The result is a kind of methodological inflation: terminology outpaces epistemic accountability, i.e., the responsibility one assumes when attempting to accumulate knowledge about a specific domain. It requires that theoretical claims be logically derivable from stated assumptions/hypotheses and connected to observations in a way that allows others to test, replicate, or disconfirm them. A field that fails to uphold this responsibility may still exhibit technical fluency or local coherence, but it no longer operates as a science in the full sense—it loses its capacity to be held answerable to the empirical world.