It is apparent that recent contributions to the literature dealing with conversion reactions are derived from a variety of premises. For our continuing study of conversion phenomena, we decided to examine critically some of the implicit and explicit assumptions of current writers, in order to evolve a conceptual model which would be useful to us as a working theory. The present paper is a statement of our current viewpoint, with comments on positions of other contributors. Historic and Semantic Considerations The now partially discarded term "hysteria" long outlived the Hippocratic concept denoting a clinical condition caused by the wandering uterus or by some variation of this (i.e., the engorged uterus, uterine "suffocation," or "furor"). Charcot's11 conception of hysteria (apparently still with some vestigial influence in continental psychiatry) implicitly accepted Morel's theory of nervous degeneration and led him to stress the presence