Which preposition to use with freakishness

of Occurrences 3%

Influenced in part, perhaps, by the Elizabethan theorists, but mainly by the freakishness of his own genius, Mr. Bernard Shaw has taken to writing plays in one continuous gush of dialogue, and has put forward, more or less seriously, the claim that he is thereby reviving the practice of the Greeks.

Which preposition to use with  freakishness