I came up with this a while ago.
A Materialist Defence of Free Will (or Free Won’t)


P1: A strictly material universe needs only naturalistic explanation. Hard determinism is said to be a naturalistic position, so human nature is determined and mechanistic according to the materialist.

P2: Findings in neuroscience, an otherwise naturalistic field, shows that we have ‘veto power’ over our impulses, that is, we can consciously choose not to do something.

C: A materialist universe does not necessitate hard determinism.



Note on P1: It follows from materialism that the physical is all there is, therefore, a naturalistic explanation for everything is sufficient. It would substantiate the position of , for instance, which is that: ‘Free will is an illusion. Our wills are simply not of our own making. Thoughts and intentions emerge from background causes of which we are unaware and over which we exert no conscious control. We do not have the freedom we think we have.’[1] The hard determinist position can be summed up in this sentence: ‘your brain is making choices on the basis of preferences and beliefs that have been hammered into it over a lifetime - by your genes, your physical development since the moment you were conceived, and the interactions you have had with other people, events, and ideas.’[2] The law of cause and effect reigns supreme here.

Note on P2: If a materialistic universe relies entirely on naturalistic explanations, then surely the finding of a ‘veto power’ is relevant, affirming a compatibilist position to free will at the very least? ‘Free won’t’ as it is called, is the term given, where we can consciously inhibit an impulse to do something, thus restoring the notion of free choice. The idea stems from an experiment by ((((((((((((Benjamin Libet)))))))))))), whose research showed that the neural impulse to do something, such as flexing one’s wrist, preceded the action by about half a second, indicating that we aren’t consciously making decisions. (This was done via EEG readings.) However, subsequent research showed that we have a window of around 150 milliseconds to ‘veto’ this neural impulse, which can be seen as a conscious decision not to do something - not free will exactly, rather, free won’t.[3]

Note on C: ‘Degrees of freedom’ exist.[4] They are not the same for everyone - the mentally handicapped or psychopaths clearly are restricted in their freedom - but this is different from concluding that we are solely determined by background causes. Therefore, the strict materialist is not necessarily condemned to belief in hard determinism.

References
[1] , Free Will (New York: Free Press, 2012), p.5.
[2] Ibid, p.41.
[3]https://www.psychologytoday.com/blog/dont-delay/201106/free-wont-it-may-be-all-we-have-or-need
[4] https://moralarc.org/wp-content/uploads/2014/12/137.FreeWont.pdf

A friend of mine criticised the 'veto', claiming that this power still has to come from somewhere. I think this implied that it would have a metaphysical or generally non-physical source.
Criticise this all you want, agree with it, destroy it - just be constructive.