Atran's treatment of classification suggests a need to recognize the d
ifference between ontological categories and less metaphysically funda
mental distinctions. The shift that scientists have made from classes
to individuals may not be as pervasive as he proposes, and the same ma
y be said for the abandonment of essences. It is also possible that th
e sort of causality that is of concern to scientists plays a role in f
olk classification.