“If God exists man cannot be free. But man is free, therefore God cannot exist. Since God does not exist all things are morally permissible” (Jean-Paul Sartre).
I have heard people use this argument trying to disprove the existence of God. Jean-Paul Sartre made a presupposition here that he did not qualify. He assumes that God’s existence and man’s free will are not compatible with each other. What is the basis for this assumption?
C.S. Lewis writes in The Problem of Pain of the dilemma of man’s free will and God’s sovereignty in relation to morality and evil in the world. His conclusion is the opposite of Sartre’s; if God exists then by necessity man must have free will. God would not have created anything but a bunch of robots if he did not give man free will. Because man has free will, he is free to choose right and free to choose wrong and evil. This is why there is evil in the world, not because God is behind it, but because man has free will to choose to do evil. Man has free will to choose to go against God’s moral standards.
Because God exists, the last sentence of Sartre’s statement here is also disqualified. If God exists then by necessity there is a moral right and wrong, and therefore not all things are morally permissible. If God exists, then he created all things within a certain framework of reality. This framework must have certain rules and boundaries, both in the physical realm of the creation itself, and in the spiritual. The spiritual realm must have moral boundaries. This must be true if God exists. And if God exists and moral boundaries exist, then all things are not morally permissible, but certain things are right and certain things are wrong. This is inescapable.