 In On the Cognition and Sensation he undertakes to erase the traditional sharp division between the mental and the physical in two specific ways: First, he advances a theory that minds and mental conditions consist in forces [Kräfte] that manifest themselves in people’s bodily behavior—just as physical nature involves forces that manifest themselves in the behavior of bodies. Officially, he remains agnostic on the question of what force is, except for conceiving it as something apt to produce a type of bodily behavior, and as a real source thereof (not merely something reducible thereto). This, strictly speaking, absolves his theory of certain common accusations (for example, H.B. Nisbet and Frederick Beiser’s characterization of it as “vitalist”). But it also leaves it with enough content to have great virtues over rival theories: (1) The theory ties types of mental states conceptually to corresponding types of bodily behavior—which seems correct (e.g., the desire to eat an apple seems not just contingently but conceptually tied to behavior that tends toward apple-eating), and which therefore marks a point of superiority over both dualistic theories and mind-brain identity theories. (2) On the other hand, the theory avoids reducing mental states to bodily behavior—which again seems correct, given such obvious facts as that we can be, and indeed often are, in token mental states that happen to receive no behavioral manifestation at all, and which hence constitutes a point of superiority over behaviorist theories. (3) Moreover, Herder’s official agnosticism about what (mental) force is can be seen, not as the theoretical weakness it might seem to be, but as showing his recognition of the important conceptual fact (recently exploited by functionalists in their “multiple realizability argument”) that although the concepts of mind and mental conditions imply a real source of a type of behavior, they do not imply anything about the nature of that source’s constitution.