The book deals with thinkers and movements that were embraced by many second-century religious seekers but which are now largely forgotten or known only as "e;heretics"e;: Basilides, Sethianism, Valentinus' school, Marcion, Tatian, Bardaisan, Montanists, Cerinthus, Ebionites, Nazarenes, Jewish-Christianity of the Pseudo-Clementines, and Elchasites.