Free will emergentists are those who recognise the very real and important distinctions between the levels on which one can discuss free will. It is analogous to trying to define the fluidity of water by looking at each hydrogen and oxygen atom and assuming we can learn everything we need to know from that micro-level of examination.
The flaw in the comparison is that we do not ascribe a mystery or ethereal significance to the fluidity of water as is often explicitly or implicitly done with free will. We understand that water will behave reliably under controlled conditions and so it is also with mechanistic predictions of human behaviour were all of the information known.
The example of weather forecasting is used to paint a picture of the importance of the levels of description when discussing determinism and whether “one could have done otherwise”. While it is true that the macro level study of meteorology currently proves the most useful in understanding weather patterns, this does not mean that an ever improving understanding of the micro-level wouldn’t supersede this prediction power.
This conversation is most consequential within jurisprudence. When considering how we should treat a murderer a free will emergentist would argue that we rightly ascribe agency to the murderer and punish him accordingly. This is where the rubber meets the road in what I see as the dangers of “emergentism”. This so-called agency is usually understood not to apply in a scenario in which a person is suffering from a brain tumour because this can be medically corrected and is accepted as a case of misfortune. What I struggle to understand is why sensible people are recognising that on an atomic level free will is deterministic, but as we currently lack the technology to address the tinier and more complex discrepancies in the brain which would cause somebody to murder it is therefore fine to assume “evil character” and move on. Were we to develop a way to alter the brain physiology, as we can now do in removing tumours, wouldn’t these people suddenly realise how reliant their argument was on the lack of medical competence rather than on what is true?