Somehow Protestants have lost this concept in regards to salvation. We think that somehow we ask the Son to set us free but this is no different then the Roman Catholic belief that we "cooperate" with God; that man has the ability to do something that is good. At the root it's the same belief; a belief that drove the Reformers away.
We put together elaborate philosophies of all sorts of things to explain man's free will in choosing God. This was always a puzzlement to me. I remember reading many different discussions on various views from many sources. All of them pull bits and pieces of scripture but they ignore others. I've never was comfortable with any of these veiws simply because they don't explain some of the great conversions within scripture like Paul, Jeremiah, John the Baptist, Lydia, etc. all who were saved against their will. It doesn't explain how our Lord Jesus could simply walk up to Matthew and say, "Come follow me." and Matthew would just leave everything and go. That is the power of God and His right to elect whom He wills. I start from the premise that God saves everyone exactly the same way. These salvation experiences lie outside of the "free will" norm.
If you really want to see how "philosophically tolerant" Christians are in pondering man's relation to God, simply suggest that perhaps God predestines and elects men and see the type of reaction you will encounter. Hoo-boy. There are only two religions of the world; free will and God's sovereignty in election. And not many believe in God's sovereignty any more.
We've had this conversation many times before, but I do agree that the type of predestination represented by strict calvinistic groups does get a lot of negative attention. A lot of it is probably unfair attacks, but there are others who simply disagree and do so respectfully.
CS Lewis' idea of an inviolable framework would not violate anyone's free will, but I've had many staunch calvinists agree that everyone has free will. Some are just "so demented" they'd say, that they've got no interest in choosing anything good. They'll only and always choose their way to a depraved life.
The Reformers were confused in that they couldn't understand "secondary causes". By claiming that man has no free will and is irresistibly moved by grace, you are beginning to stray into Pantheism - the idea that everything is God. By making man an extension or robot of God, this destroys St. Augustine and many other's concept that man, while moved by the primary mover, CAN also be a secondary mover. This is possible in the natural as well as the supernatural realm. We cooperate with God to bring life into the world. And we cooperate with God to bring love into the world.
Regards