The paper whose abstract follows is available by anonymous ftp in the directory pub/papers/rosebrugh at sun1.mta.ca (138.73.1.12) as the files accs.{dvi,tex} If you download the latter you need to know that it is in LaTeX and uses the bibliography file accs.bib and Mike Barr's diagram macros, diagram.tex, both found in the same directory. Don't hesitate to contact me if you experience any difficulties or need ftp instructions. I will gladly forward a paper copy. If you request one be sure to include a full postal address. Bob Rosebrugh +++++++++++++++++++++++++++++++++++ An adjoint characterization of the category of sets Robert Rosebrugh and R. J. Wood Abstract If a category B with Yoneda embedding Y : B ---> CAT(B^op,set) has an adjoint string, U -| V -| W -| X -| Y, then B is equivalent to set. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++