On the Possibility of Libertarian Free Will

This is a brief attempt to show that while remaining unlikely, the existence of Libertarian Free Will is not an impossibility within the bounds of our current scientific and philosophical understanding.

My aim is to identify both the possibilities and any problems with them that need tackling.



First we need to acknowledge that there are effectively two causal systems in play in the world:

1) the deterministic system of our macro-scale, aggregated, classical physics. Let us call this the D-system.

2) the indeterministic system of micro-scale quantum physics. Let us call this the I-system.

It is uncontroversial that there are brain processes that operate in the D-system, unfolding deterministically. Let us call these D-processes. It may also turn out to be the case that there are brain processes that operate in the I-system, unfolding indeterministically¹. Let us assume this to be the case and call these I-processes.

For our purposes we need to imagine a D-process D  that assesses a range of possibilities from which the agent is to choose. It doesn’t matter if D is a conscious process or not. What matters is that left alone, will evolve deterministically.

However, in this case D initiates an I-process I that consists in the agent’s imagining of the future, to aid in its decision. We might characterize this event as D requesting data from I, and I returning data to D.

Since the I-system is indeterministic, the data returned will be random. It will however be constrained within the context of the data request (so for example, a request for data on choosing between cheese or chocolate is more likely to return imaginings of taste or waistlines than it is of drowning or London buses).

Data returned from I may or may not be novel with respect to previously existing data available to D. If the data is novel, then depending on its practical feasibility, it may provide additional possibilities from which D can select. Therefore the unfolding of D without the novel data from I may differ from the actual unfolding D with the novel data from I.

From this, we can see that one component of Libertarian Free Will is possible, consisting in the ability of an I-Process to return data to a D-Process, freeing the D-Process from the determinism of the D-System by way of a swerve from the deterministic system to the indeterministic system. However, this implies a random swerving, which is not good enough for Libertarian Free Will. So we will continue.



It is reasonable to suggest that the more data that is returned from I, the more likely it is that D will go on to select a possibility that only became available due to that additional data.

It may also turn out to be the case that the I-system operates in a non-temporal environment². Let us assume this is the case.

Given this assumption, the amount of data returned from I cannot depend on a variable set by D that results in a determined amount of time for I to complete the task. We say this because the amount of time used by the I-process – being that it is a-temporal – is always zero. The I-process takes place outside of both a spatial and a temporal structure.

If not determined by a variable set by D then perhaps it is reasonable to think that the amount of data returned from I is determined by something intrinsic to the I-process itself. It could be this variability in the I-process that corresponds to the conscious effort of the will, providing the non-random element of the swerve.



So if an agent exercising free will does so within the I-system, this not only implies that a function of the agent – its imagination – resides in that system, but that at least a part of that which defines its character as an agent – its strength of will – does so too. The question then becomes that of how a semi-persistent character trait can retain its integrity in an indeterministic environment.

I’ll return to this in a future post.



¹ c.f. quantum biology
² c.f. quantum gravity and emergent spacetime