Is there a middle ground between determinism and libertarianism?

Question

Is it possible that we live in a universe where some things are truly deterministic and other truly random and the difference between those two things is how their particles are arranged?

For example, I believe that it is possible to make a robot that always flips a fair coin as "heads" (The robot can control and reproduce all the forces in the robot's hand with enough dexterity to not affect the outcome of the coin flip). Now, if a human flips the coin, there is always some uncontrolled force that affects the coin (some hand trembling, where the finger nail applies the force, etc).

The robot and human both are made by particles but differ in how those particles are arranged.

Hence the "particle arrangement" of the human makes him/her been able to introduce randomness to the coin flipping event but the robot "particle arrangement" makes it impossible to introduce randomness to the coin flipping event.

Answer 1

Assuming you mean "Libertarianism"

Yes, It is possible, for multiple reasons: (Depending on how "physical" or "philosophical" you intend the question to be interpreted)

1. Both Libertarianism as well as Determinism are quite believe based and are defined in different ways or at least different "levels of strictness" by multiple people including well regarded philosophers. While we can show physical evidence for some aspects of some of those theories, including for example random versus non-random aspects of quantum physics, the "...ism" 's in general are too broad to be either proven or dis-proven as a whole.

2. Scale: Depending on the scale between macro and micro, there is a tendency between deterministic behavior at the macro scale (e.g. earth revolving around the sun) and indeterministic or seemingly random behavior at the micro level (e.g. single electron)

3. Seemingly Random behavior depends on how well controlled the environment and the power/resolution of observation is. Partially depending on the scale we can control all relevant aspects better or less accurately. Your robot is a good example of this - add external magnetic or electric fields, air-draft and bounciness of impact surface to the control

4. The "mind-body problem" including the question of whether there is actually a "free will" is philosophically unsolved, meaning there is no proof one way or the other - therefore all options are "possible"

The robot you propose is a good example, another one is a large enough bomb blowing up a house. The result is "deterministic" in the sense that we know in advance that the house will be blown up. It's also not deterministic in the sense that we don't know exactly where each piece of the house will end up - which highlights the aspect of 'scale' and resolution of observation (how closely and accurately we actually look at the result). Caveat: Just because we don't know where each piece ends up doesn't mean that their positions are not pre-determined according to some interpretations.

Thus, with some interpretations of 'determinism', there can be a middle ground, but there are at least two interpretations for which this is not possible:

Strict religious interpretation - Determinism means a supreme being controlling every aspect of our universe, including behavior of every single quantum while libertarianism means that this being doesn't exist or at least doesn't exercise its power for control and thus leaves room for "chance" or "free will".

Very strict Determinism - EVERYTHING is determined by a strict chain of events from which it is impossible to stray. That would include every particle/quantum in the robot example and even each of those particles' history. This would obviously preclude both chance and human meddling i.e. free will (as even our neurons are part of the strict chain as particles) and thus any 'Libertarianism'.

Answer 2

Is it possible that we live in a universe where some things are truly deterministic and other truly random and the difference between those two things is how their particles are arranged?

Perhaps. Consider unstable Lagrange points, which have the property that objects traveling through them have an undetermined aspect to their ultimate trajectory. This is because at such points, the forces of gravity cancel, and infinitesimal differences can make all the difference. This means that infinitesimal forces can have a non-infinitesimal effect. Now, must our universe allow true unstable Lagrange points? My don't-have-a-physics-degree hunch is "no", either by simply disallowing certain starting configurations, or quantizing space somehow.

We could then consider whether allowing the forces of gravity to cancel merely allow randomness to rear its head, or actually allows another causal order to manifest itself. Something to be wary of is an implicit identification of 'determinism' with general causation, over against singular causation (comparison). In my experience, compatibilism is defined against general causation, not against any and all forms of determinism. For example, from the Stanford Encyclopedia of Philosophy:

Within this essay, we shall define determinism as the metaphysical thesis that the facts of the past, in conjunction with the laws of nature, entail every truth about the future. (Compatibilism § Determinism)

I've taken to describing this as monocausation: there is one causal power in play, constituted by the laws of nature (not to be confused with scientific laws, which are understood to be approximations). And so, compatibilism is an attempt to achieve something that looks like free will without adopting a different metaphysics of causation. In other words: there is an implicit commitment to the denial of agent causation, where agents are irreducible sources of causation in addition to the laws of nature. Of course there are costs to abandoning monocausation: how exactly would two causal powers interact if there are no "global rules"? Every philosophy has to bite its bullets.

You can find a fairly well-developed alternative to general causation/​determinism/​monocausation in Gregory Dawes' Theism and Explanation. There, he asks whether "God did it" could possibly suffice as an informative explanation. Let's not get too caught up in theology; what he's really asking is whether agent causation could possibly provide explanatory power over and above what you get with general causation. His answer is yes: a good explanation has to rule out possibilities, and there is a way to do that other than via scientific laws (e.g. [partial] differential equations): by rationality and what he calls the "optimality condition". I can predict the future based on cranking mathematical laws on state, and I can predict the future by knowing what courses of actions agents consider more optimal to achieve their goals.

What you're really fighting here, is an "as if" method of explaining, exemplified by Daniel Dennett's intentional stance. Instead of teleology, you get the appearance of it, built on general causation: teleonomy. That which appears designed actually evolved. You may think you love your significant other, but it's just oxytocin. There are attempts to hide this reduction to general causation (e.g. Sean Carroll's Poetic Naturalism), but it's there.

Libertarian free will, as I understand it, is an attempt to break out of the straight jacket that is general causation, but sometimes (often?) without understanding that the reaction is not to all forms of determinism, but only some of them. A great criticism of what is called 'determinism' can be found in mathematical biologist Robert Rosen's Life Itself. He looks at the specific mathematical forms to which all science was supposed to ultimately reduce—basically, differential and partial differential equations—and argued that it's not even possible to define 'life' with such spartan tools. There are simply more ways that causation can happened, he argued. Were the advocate of libertarian free will to avail himself/​herself of this critique, I suspect some interesting progress could be made. Then again, perhaps I am simply ignorant of the latest, best literature on free will.

Answer 3

To have a "middle ground" pre-supposes that the ideas of Libertarianism and Determinism are at either end of a scale, but generally they are not.

Firstly, Determinism doesn't disallow randomness. Randomness is a statement about our uncertainty of an outcome, not its lack of determinism. Lack of determinism is spontaneity, the coming into being of an effect without a cause.

Secondly, as Conifold points out in comments, Libertarianism is not just the opposite of Determinism in terms of randomness (spontaneity of effect), it is a statement about the ability of a person (or other agent in some schools) to make a free choice unconstrained by pre-existing events. In order to do this, most philosophers of Libertarianism invoke a Dualism, allowing that there is a world of the mind which does not follow normal physical laws such as cause and effect and it is from such a world that our intentions arise.

Thus the two schools have binomial differences, not graduated ones. Dualism or Monism, I personally cannot see how a middle ground could exist between these two positions, either world of mind exists or it doesn't. If it does then Libertarianism becomes true de facto, as that world was postulated entirely to support the theory. If it does not then whilst strict Determinism might still be in question at a quantum level, Libertarianism is certainly impossible as every effect at a human scale must have a cause.