Calvin's view of "natural man" is perverted.
Calvin's view of the natural man is founded on Scripture. Read your Bible.
For to be carnally minded is death; but to be spiritually minded is life and peace. Because the carnal mind is enmity against God: for it is not subject to the law of God, neither indeed can be. So then they that are in the flesh cannot please God." -- Romans 8:5-8 "For they that are after the flesh do mind the things of the flesh; but they that are after the Spirit the things of the Spirit.