Conversation so far:
What was unusual about Schacht's method?
As a whole, Origins critiques the methods and standards of ḥadīth verification, an early and centrally important stage in the formation of Islamic jurisprudence.
What is one of the sources of Islamic law?
The Quran
What other sources did Joseph Schacht say Islamic law comes from besides the Quran?
the Sunnah (the body of traditional social and legal custom and practice of the Islamic community), Qiyas (the process of deductive analogy ), andIjma (the consensus/agreement of Muslim scholars)
Was Joseph Schacht a great influence on other scholars of Islam besides Muslims?
According to David Forte, nearly all Western Islamic scholars agree that Schacht's evidence against the authenticity of the traditions is virtually unassailable.“

Question: What was his argument?
Self-contained rewrite: What was David Forte's argument on Schacht's influence on Islamic scholars?