Neither until I caught myself one day trying to justify my behaviour with both ideas. Best metaphor is probably the one that says that you wake up in a small boat on a large swiftly flowing river (determinism). You have a piece of wood that is too small to be an effective paddle but big enough to act as a rudder of sorts (free will). While you have no ability to paddle against the current let alone choose what river you are on, you do have the ability to influence which side of the river you travel. The rudder offers a little bit of directional flexibility so you can avoid rapids, find calm spots etc while you travel downstream. Not a perfect picture but close. 🙂