Which preposition to use with unfruitful

in Occurrences 7%

The scholastic philosophy, even if it was barren and unfruitful in leading to new truths, yet confirmed what was valuable in the old systems, and by the severity of its logic and its dialectical subtleties trained the European mind for the reception of the message of Luther and Bacon; and this was based on deductions, never wrong unless the premises are unsound.

Which preposition to use with  unfruitful