Association therefore never comes into play as an autonomous force; it is never the word suggested which 'induces' the reply in the manner of an efficient cause; it acts only by making probable or attractive a reproduction intention; it operates only in virtue of the meaning it has acquired in the context of the former experience and in suggesting recourse to that experience; it is efficacious to the extent to which the subject recognizes it, and grasps it in the light or appearance of the past.