The Common Sayings Source is one of many theories that attempts to provide insight into the Synoptic Problem. The theory posits that the Gospel of Thomas, a sayings gospel, and the Q source, a hypothetical sayings gospel, have a common source. Elements of this Common Sayings Source can be found in the text of the Gospel of Thomas and what scholars are proposing existed in the Q source. The high level of similarities between the two sources suggests that both documents are later redactions of a single source, the original Common Sayings Source, which was then redacted by different groups to suit their own needs.
The main proponent of the theory is John Dominic Crossan. He chaired the historical Jesus section of the Society of Biblical Literature and was co-director of the Jesus Seminar.[1] The theory is based on research previously done by John Kloppenborg on the Q source, William Arnal on the Gospel of Thomas, and Stephen Patterson on the Common Tradition. John Dominic Crossan uses these scholars’ research and combines them to create the theory of the Common Sayings Source.
This source provides insight into the Synoptic Problem and lends more evidence for the two-document hypothesis and the Q source.[citation needed]