In chapter six his book "What does it all mean?" Thomas Nagel (Professor of Philosophy, New York University) covers the topic of free will, yet somehow avoids coming to any clear conclusion, in the following text I will try to deduce what his answer to the question "How Free Am I?" would be.
Although Nagel describes determinism with great clarity and conviction he goes on to reject it on the grounds that it negates both individual and social responsibility. He seems to believe that if what we do and say is both determined and inevitable then we cannot be held responsible for our actions, we can no more punish a criminal or praise a saint that punish or praise an inanimate object like a rock. So he is not determinist.
The case against determinism is argued with much less conviction, for if it was not determined then what caused it, as Nagel puts it: "� if the act wasn't determined in advance, by your desires, beliefs, and personality, among other things � how was it your doing?". Nagel seems to believe, at this point in the text, that what ever way we look at it we are free from responsibility, which is a very dangerous and hedonistic way of looking at life and responsibility. Happily Nagel goes on to describe what he calls "casual determinism".
Casual determinism is like determinism in that ones decisions are thought to predetermined, but unlike determinism our personal a social responsibility requires that our actions be predetermined, the thought behind this is that for an action to be your own it must be determined by causes within you, for example you wanted the cake and not the apple, so therefore your want overriding other forces determined your action. The key word being your. People who believe this believe that if it wasn't determined then it happened out of the blue and is unexplainable, and it is the unexplainable, not determinism, that threatens freedom.
Nagel rejects this view as well, but on the grounds that it feels wrong, not by intellectual argument. In fact he rejects casual determinism with the same arguments that he used to reject determinism. Which is fair, because "casual" is just another way of looking at it. Nagel seems to think that the choice itself is a philosophical illusion, which to me looks like a leaning towards determinism that he cannot accept.
I think that if asked "How free am I?" Thomas Nagel would avoid answering, because he knows that he does not know, and perhaps respond with a question. He may explain the different arguments, but he would not give a clear and simple opinion.
Personally I lean towards casual determinism, but like Nagel, feel uncomfortable with it, although unlike Nagel, I would happily argue it through to a solid conclusion.