Free will is agency and volition. There's nothing mysterious about it. It doesn't mean that the "laws" of physics are being violated nor does it mean that any chains of causality are being broken. It also doesn’t prove anything about gods, souls, spirits or ghosts in the machine. It’s a completely natural product of evolution.
Free will requires causality. Acausal events are essentially random. There is no choice in randomness, only chance. Therefore, anyone still stuck on the notion that free will is “free from causality,” is simply wrong. Free choices aren't random. They aren't free from being caused. There is no mysterious uncaused causer but rather they are caused in the right way based on the beliefs and desires of the agent. A choice is made freely when the agent could have chosen otherwise if the agent’s beliefs and desires were different.
Free will skeptics might try to claim that our desires are uncontrollable or that neuroscience proves we don’t have volition, but they would be wrong. Here are some scientific journals that have had articles that agree with human agency and volition:
Volition and Conflict in Human Medial Frontal Cortex
Current Biology, Volume 15, Issue 2, 122-128
"Controversy surrounds the role of human medial frontal cortex in controlling actions [1, 2, 3, 4 and 5]. Although damage to this area leads to severe difficulties in spontaneously initiating actions , the precise mechanisms underlying such “volitional” deficits remain to be established. Previous studies have implicated the medial frontal cortex in conflict monitoring [7, 8, 9 and 10] and the control of voluntary action [11 and 12], suggesting that these key processes are functionally related or share neural substrates. Here, we combine a novel behavioral paradigm with functional imaging of the oculomotor system to reveal, for the first time, a functional subdivision of the pre-supplementary motor area (pre-SMA) into anatomically distinct areas that respond exclusively to either volition or conflict. We also demonstrate that activity in the supplementary eye field (SEF) distinguishes between success and failure in changing voluntary action plans during conflict, suggesting a role for the SEF in implementing the resolution of conflicting actions. We propose a functional architecture of human medial frontal cortex that incorporates the generation of action plans and the resolution of conflict."
Human volition: towards a neuroscience of will
Nature Reviews Neuroscience 9, 934-946
"The capacity for voluntary action is seen as essential to human nature. Yet neuroscience and behaviourist psychology have traditionally dismissed the topic as unscientific, perhaps because the mechanisms that cause actions have long been unclear. However, new research has identified networks of brain areas, including the pre-supplementary motor area, the anterior prefrontal cortex and the parietal cortex, that underlie voluntary action. These areas generate information for forthcoming actions, and also cause the distinctive conscious experience of intending to act and then controlling one's own actions. Volition consists of a series of decisions regarding whether to act, what action to perform and when to perform it. Neuroscientific accounts of voluntary action may inform debates about the nature of individual responsibility."
To Do or Not to Do: The Neural Signature of Self-Control
The Journal of Neuroscience, August 22, 2007, 27(34):9141-9145
"Voluntary action is fundamental to human existence. Recent research suggests that volition involves a specific network of brain activity, centered on the fronto-median cortex. An important but neglected aspect of intentional action involves the decision whether to act or not. This decision process is crucial in daily life because it allows us to form intentions without necessarily implementing them. In the present study, we investigate the neural correlates of intentionally inhibiting actions using functional magnetic resonance imaging. Our data show that a specific area of the fronto-median cortex is more strongly activated when people prepare manual actions but then intentionally cancel them, compared with when they prepare and then complete the same actions. Our results suggest that the human brain network for intentional action includes a control structure for self-initiated inhibition or withholding of intended actions. The mental control of action has an enduring scientific interest, linked to the philosophical concept of "free will." Our results identify a candidate brain area that reflects the crucial decision to do or not to do."
We have free will. It just isn't anything magical like some might have thought.
At this point there are usually objections in the form of unprovable metaphysical claims about determinism. Often something to the effect is said “the initial conditions of the universe along with the laws of physics absolutely determine the inevitable outcome of all future events”. This is based on a literal interpretation of the word "law". In reality, scientists don't think of the laws of nature as real laws at all. They don't govern or control anything. They are descriptive not prescriptive. They are simply true statements about nature. No more. No less. Determinism is not a threat to human agency and volition.
The same thing goes for causality, talk of forces, and so on. This is all detailed in the regularity theory of causation. The theory does away with all mysterious causal necessity. Instead we say that one event causes another if it regularly follows it. A good example is the effect of the Moon’s mass on the Earth’s oceans. There is no mysterious causal force linking the Moon and the Earth. It’s completely incorrect to say that the Moon’s gravity causes the Earth’s tides. There’s no preceding event that causes anything. There’s simply an observable relationship between any two massive objects. If you want to go beyond observation, if you want to claim that there’s something that really causes it, that’s an unprovable metaphysical claim outside the realm of science. These metaphysical claims are ultimately superfluous and don’t explain anything. This is why the regularity theory of causation appeals to most empiricists. Under this interpretation (and many other equally valid interpretations since none can be confirmed or denied) there exists a more rational theory of causality that doesn’t require inevitability. If you want to go as far as to claim that all things are inevitable, you do it on unempirical grounds.
Many free will skeptics still can’t help but feel like I’ve pulled a fast one on them. The scientific evidence that all free will skeptics claim to have been waiting for, in the end, is rejected. When recent advances in neuroscience are no longer able to give their position credibility they retreat into more unprovable metaphysical claims about determinism. They just know that they have no choice in the matter, even if they can’t prove it. The ultimate final desperation argument when all recent empirical data points to humans having agency and volition is to claim that although humans behave exactly as if they are agents and have volition, they don't really because of [insert some philosophical sophistry about determinism and causality here]. This is much like the claim that "this magic cloth is invisible only to those who are stupid or unfit for their position". I'm sorry but I just don't buy it. Whether humans possess some certain property or not is an empirical question best left up to verification by science and not certain philosophers that tend to tie themselves in knots over imaginary problems while ignoring the reality that science can demonstrate.