fountainhead
From Longman Dictionary of Contemporary Englishfountainheadfoun‧tain‧head /ˈfaʊntənhed $ ˈfaʊntn-/ noun [singular]
COME FROM/ORIGINATEthe origin of something SYN sourceExamples from the Corpusfountainhead• Keynes, as we shall see presently, was on his way to being the new fountainhead of conventional wisdom.