ABSTRACT
As a program for psychological inquiry, mental mechanism had one great methodological advantage: it could undertake to grapple with psychological phenomena without recourse to premature physiological speculation. As a program of mechanistic explanation, however, mental mechanism had one very grave shortcoming. The central aim of mechanism was to explain all things in terms of “matter in motion". Toward the middle of the eighteenth century we find another psychological enthusiasm beginning to gain momentum. Since its emphasis was upon the activities of the body, and since these activities were regarded solely as the result of “matter in motion,” this new enthusiasm is best described as physiological mechanism. Physiological mechanism was based upon two quite distinct assumptions: that the activities of the body can be exhaustively accounted for in terms of familiar mechanical principles and that mental phenomena are nothing more than the products of these activities of the body.
