A recent thread on free will did not meet the criteria of the forum, but perhaps a similar discussion could be generated by borrowing directly from the example in the rules: "The research of Benjamin Libet suggests that our decisions to act occur before our conscious awareness of them. Isn't this a serious problem for the idea of free will? http://en.wikipedia.org/wiki/Benjamin_Libet". Specifically, does this imply an either/or battle between determinism and free will? One might try adopting the approach that the neurological correlates of free will are deterministic (if one does wish to adopt a kind of dualistic picture where all that is physical is deterministic and free will is housed in some extra-physical seat of conscious choice). To summarize, Libet's research, and a host of follow-on studies of various kinds, suggest that when you look at the neural correlates of consciousness, as they have been identified (a tricky business in itself but the only one that neuroscience can access directly), you typically find that the experience of consciousness is a rather slow process, compared to the timescales on which we sometimes have to make (split second) choices that nevertheless are considered "conscious", albeit "snap", decisions. Does this mean that a decision we must make rapidly, say a life-or-death choice about whether to jump into a river to save someone, are not things we can attribute to free will, when a more long-term decision (like who to marry) might be? That might be an interesting issue, to try to draw the line between what is "conscious" and what is just "instinct", but personally, I would look in a different direction-- I would look critically at the very assumption that physically identifiable processes are deterministic in some "absolutely true" way, such that they could preclude a concept of free will. Instead, determinism is a model, just like all scientific concepts. It was never intended to describe how reality actually is, and it is never used for that. Instead, the model of determinism is applied to making predictions about outcomes, and in some situations, we know this model leads to good predictions, and in others, it has more limited success. For example, determinism in weather prediction leads to the fairly absurd concept that a butterfly can "change the weather", when a much more natural conclusion is that the butterfly is schooling us in the limitations of deterministic thinking. And in quantum mechanics, that which is deterministic is a process that does not lead to definite predictions, such that the outcomes of experiments are not in fact determined, are are of uknown determinism at best. I feel these should all be taken as a cautionary tale about the fundamental incorrectness of the equation physical = deterministic. So in this sense, I would agree that there is something fundamental in how we do science that requires the determinstic model, but I disagree that this means we know the universe itself evolves deterministically-- rather, our scientific understanding of the universe involves placing the template of determinism against the universe, so a deterministic universe is what we get-- with all its blind spots. The deterministic approach produces a powerful, but the evidence is, an incomplete, way to think about things, as per the chaos and quantum mechanics examples.