Which preposition to use with heterogeneity

of Occurrences 5%

I have often remarked, and it cannot be too often remarked (vain as this may sound), that this essential heterogeneity of regret and remorse is of itself a sufficient and the best proof of free will and reason, the co-existence of which in man we call conscience, and on this rests the whole superstructure of human religionGod, immortality, guilt, judgment, redemption.

Which preposition to use with  heterogeneity