  A history of philosophical logic is yet to be written.   Though philosophical logic has traditionally been distinguised from mathematical logic, the distinction may well be incidental in relation to the overall goals of the subject, since technical rigor and the use of mathematical methods seem to be essential in all areas of logical research. However, the distinction between the two subfields has been magnified by differences in the sorts of professional training that are available to logicians, and by the views of individuals on what is important for the field. 