Deep core beliefs represent an important yet theoretically underspecified concept within the Advocacy Coalition Framework (ACF). This underspecification can (in part) be attributed to the ad hoc way in which ACF scholars have defined and measured the concept over time. To overcome this, we advocate the development and future use of a standardized metric for measuring deep core beliefs in ACF studies. Such a measure, we contend, should be multidimensional, generalizable, measurable using multiple techniques, and broad enough in scope to operate across virtually all policy domains. Using these criteria as our benchmark, we evaluate the viability of cultural theory (CT) as one such metric. In short, we find that CT meets all of these criteria, and therefore provides ACF scholars with a way to measure deep core beliefs across enduring public policy disputes that are demarcated by conflicting belief systems. Accordingly, we advocate its use in future studies.