Which preposition to use with indoctrinator

of Occurrences 1%

Oh! had the first indoctrinators of Christian feeling, while enlisting the "divine Plato" into the service of diviner charity, only kept the latter just enough in mind to discern the beautiful difference between the philosopher's unmalignant and improvable evil, and their own malignant and eternal one, what a world of folly and misery they might have saved us!

Which preposition to use with  indoctrinator