The granularity of things whose nature is described as they are acknowledged, thus it depends on experimental evaluation, degree of certainty, etc. This is typically done in some variety of epistemic logic (it requires at least the meta-level predicates: 'knows' and 'believes'. For example, the predicate 'spherical(x)' is true of any physical object at the '_epistemic' granularity if no imperfections are detected by the measuring device used (even body senses).