Joe asked this question under another topic and I wanted to give it its own thread... I hope that is ok Joe? Joe, Well my answer depends on what type of hardening to which you are refering. There are two types of biblical hardening; each are described in detail below: 1. Self-Hardening of the heart goes beyond the tragic obtuseness of our inherited condition in the Fall of man. Working on the fertile soul of our innately immoral hearts, the act of sinning hardens the heart into a stubborn rebellion against all that is good. So, people may harden their own hearts, in sinful rebellion, in bitterness, or in sheer self-will. (Ex. 9:34-35; 2 Chron. 36:13; Zech. 7:12; Dan. 5:20; Eph. 4:18; Heb. 3:12-15) This type of self-hardening is most clearly seen in Zech. 7:11-13: "Your ancestors would not listen to this message. They turned stubbornly away and put their fingers in their ears to keep from hearing. They made their hearts as hard as stone, so they could not hear the law or the messages that the LORD Almighty had sent them by his Spirit through the earlier prophets. That is why the LORD Almighty was so angry with them. ‘Since they refused to listen when I called to them, I would not listen when they called to me,’ says the LORD Almighty.” 2. Judicial Hardening -- In a few instances such as Pharaoh and the Egyptians (Ex. 7:3; 9:12), Sihon, king of Heshbon (Deut. 2:30), and the Hivites living in Gibeon (John 11:19-20), it is said that God hardened their hearts. Apparently these people were so irremediable in their rebellion against God that God entered into the hardening process so that he could accomplish his purposes in spite of, and yet in and through, that hardenness. It is God's prerogative, as God, to do this (Rom. 9:18-21). That they are morally responsible for their condition is a theological given, and we are warned not to harden our hearts as they did, a command that would make no sense if hardening were simply God's act (1 Sam. 6:6). Israel's hardening as a nation was an act of self-hardening followed by God’s act of judicial hardening as clearly portrayed in the scripture (Matt. 23:37; Rom. 10-11). God tells Isaiah that Israel, with its calloused heart, will reject him as God's messenger when he goes to them (Isa. 6:9-10). The event was taken as prophetic by Jesus (Matt. 13:14-15) and Paul (Acts 28:25-27) as referring to Israel's rejection of Jesus as God's Messiah. For Paul, Israel's hardening paved the way to a ministry of ingrafting the Gentiles (Rom. 10-11; Acts 28:28) and was not intended by God to be final, but only until the fullness of the Gentile’s ingrafting was accomplished. Only the Word of God has the power to cut or pierce a hardened heart (Heb. 4:12) and he has given that word through his Son, the Apostles, the scriptures and by his Spirit all of which can be resisted and ignored as seen throughout the Bible as the hardenness and callousness of the heart only grows thicker with each act of rebellion. According to scripture only those in a hardened state are unable to see, hear, understand and believe (Acts 28:26-28: John 12:39-40). Calvinism’s doctrine of Total Depravity teaches that everyone is born in this condition due to the Fall of Man. The doctrine of Original Sin can clearly be seen in the scripture, but the Calvinistic system takes this foundational truth one step further by teaching that after the Fall God removed men’s capacity to respond to the call of the gospel, yet God, according to Calvinism, still holds men responsible for that response. I know this is probably much more than you were wanting but I've studied this doctrine extensively for the last 2 to 3 years and well, you asked. Sorry for the length. Blessings to you.