When God is here spoken of as hardening some of the children of men, it is not to be understood that God by any positive efficiency hardens any man's heart. There is no positive act in God, as though he put forth any power to harden the heart. To suppose any such thing would be to make God the immediate author of sin. God is said to harden men in two ways: by withholding the powerful influences of his Spirit, without which their hearts will remain hardened, and grow harder and harder; in this sense he hardens them, as he leaves them to hardness. And again, by ordering those things in his providence which, through the abuse of their corruption, become the occasion of their hardening.

God hardens some men's hearts, as he did Pharaoh's, and he wills to harden them, or he hardens them according to his decreeing will; "Whom he will he hardens", (Romans 9:18) this he does not by any positive act, by infusing hardness and blindness into the hearts of men; which is contrary to his purity and holiness, and would make him the author of sin; but by leaving men to their natural blindness and hardness of heart; for the understanding is naturally darkened; and there is a natural blindness, hardness, and callousness of heart, through the corruption of nature, and which is increased by habits of sinning.

First, the offering of occasions which can be procured only by the peculiar providence of God by the concourse of circumstances and the proposition of objects, fitted to move faculties constituted in this or that way (in which manner God does not infuse wickedness into the minds of men, but draws out into action the wickedness latent there).

For in those people God did not make the common sins but found them there, as we have noted before. And although God, in his just but to us hidden judgment, does abandon and harden them more and more (Romans 9:18), yet it is they who by their own free choice first become hardened (Romans 11:7) and abandon the benefits of general providence; they abuse God’s longsuffering, as Paul testifies in Romans 1:18, 26, and 28.

Not by permitting the evil action, because he is bound by no law to hinder sin. Not by determining it; for as he who puts out a fire so that it may not spread further is not the cause of the fire, so he who fixes bounds to sin is not the cause of sin. Not by directing it to a good end; for as it is the highest art to prepare a wholesome medicine from venomous animals, so it is glorious for God to draw light even out of darkness, and something good out of evils.