Conversation so far:
What was unusual about Schacht's method?
According to Schacht the rules and standards of Islamic law are derived from four primary sources.
What is one of the sources of Islamic law?
from the Qur`an.
What other sources did he say Islamic law comes from?
from the hadith comprising the sunna of the Prophet Muhammad and his Companions, from the consensus or ijma' of the Muslim community and from analogical reasoning or qiyas.
Was he a great influence on other scholars of Islam?
CANNOTANSWER.

Question: What was his argument?
Self-contained rewrite: What was Schacht argument?