Marc Shapiro puts an explicit contemporary context on this remarkable collection of sources that disagreed with one part or other of Maimonides' Thirteen Principles—the beliefs Maimonides asserted were absolutely necessary to be considered a believing Jew and to attain the World to Come. By showing the extent to which past authors disagreed with those Principles, Shapiro seeks to debunk assertions by contemporary writers that place those Principles at the core of Orthodox belief.