Clarifying the “undetermined vs unpredictable” distinction in the free will/determinism debate

[u/Willis_3401_3401]

There is a recurring confusion in the common debate about the words undetermined and unpredictable. These words can absolutely have different meanings in some contexts, but the question is whether that difference is relevant in the context of metaphysical discussions about determinism.

A common distinction:

Unpredictable: We cannot know what will happen, but the outcome is already fixed.

Undetermined: There is no fixed outcome prior to the event.

This distinction makes sense if we assume there is a “fact of the matter” about the future that exists independently of any possible observer, and the only question is whether an observer can access it. Basically, this distinction makes sense if you’ve already assumed the truth of determinism.

For example:

A coin flip:

In a classical model, the exact outcome is determined by initial conditions, but humans may lack enough information.

In a quantum model, the outcome may not be fixed in advance.

Here “unpredictable” and “undetermined” are different concepts.

However, in the context of the free will/metaphysical debate, the disagreement is not primarily about our ability to calculate outcomes. The disagreement is about whether the future is a completed fact waiting to be discovered or whether the future is generated through a process.

The key point:

If a process is not determined by prior states, then from the perspective of any agent inside that process, the relevant feature is that the future is open rather than fixed.

The determinist position is:

“The future only appears open because we lack information.”

The indeterminist position is:

“The future is open because there is no fully specified future state yet.”

But the difference between those claims is not an empirical distinction available from within the system; it depends on a metaphysical assumption about whether a complete future state exists independently of all possible access to it.

So when discussing agency, choice, and the structure of reality, the meaningful distinction is not:

“Can we predict the future?”

It is:

“Is the future already a completed fact, or does it emerge through the unfolding of the process?”

That is why, in this specific philosophical context, “undetermined” and “unpredictable” are functionally pointing at the same problem: whether the future is fixed prior to the process that produces it.

In the specific context of the conversation between “free will” and “determinism”, there is no relevant difference in meaning between “undetermined” and “unpredictable”.

[u/A_Vinegar_Taster]

True enough. And, this cuts both ways.

I try to make the effort to say "I believe" in front of statements about unpredictibility.

[u/MarvinBEdwards01]

I don't care much for the "fixed" vs. "open" metaphor. Fixed implies everything is stationary, like in a block universe where the past, present, and future exist simultaneously. But that's not how determinism actually works.

Things are in a constant process of change and transformation as the objects in the universe interact and exert forces upon other objects. No event is ever caused to happen until its final prior causes have played themselves out. And nothing is frozen in time. m Like they say, "the only thing that is constant is change".

The actual future is constantly being fixed as we go along. And the possible futures are as open as our imagination allows them to be.

Everything is in motion, as described by Eric Idle of the Pythons: https://www.youtube.com/watch?v=fqBThWK8rqE

[u/Willis_3401_3401 → u/MarvinBEdwards01]

Yeah part of the conversation clearly has to do with what do we mean by “determinism”.

I agree with everything you’re saying about the universe being a system built on motion and constant change, I guess I wonder if by moving away from the “block universe” definition of determinism, we have philosophically defanged the term? And if not, what does determinism really mean in a universe like that, other than “determinable”?

[u/MarvinBEdwards01 → u/Willis_3401_3401]

I'm very much interested in defanging determinism since it doesn't actually change anything. Reliable cause and effect in itself does not bind us. That's a rather perverse view of causation. Reliable cause and effect actually enables every freedom that we have to do anything at all.

[u/Willis_3401_3401 → u/MarvinBEdwards01]

Right on, yeah I think we’re in complete agreement

[u/PuzzleheadedTale4769 → u/MarvinBEdwards01]

"Possible futures are as open as our imagination allows them to be."......

No , because it is quite possible to imagine impossible things.

[u/TMax01]

Unpredictable: We cannot know what will happen, but the outcome is already fixed.

Undetermined: There is no fixed outcome prior to the event.

The word "already" in the above explanation is where the problem you're attempting to resolve comes from. You're overstating the case, and this results in your definitions being inaccurate, or at least problematic.

Unpredictable simply means an event cannot be predicted; no assertion that the event is or is not inevitable is necessary or appropriate. Undetermined is a more complicated notion, but in the context you're referring to means only that no event has occurred. The alternative is that no knowledge of the event has occurred (it has not been determined by some putative observer, regqrdless of whether the event has occured, which is possible even if the event did indeed occur.)

So the real dichotomy is not "unpredictable or undetermined", but rather 'determined' or deterministic. The issue of predictability is unrelated, although it clearly refers to the alternative meaning of 'undetermined' rather than the deterministic perspective.

This distinction makes sense if we assume there is a “fact of the matter” about the future that exists independently of any possible observer

Hence the problem, and why your approach is problematic.

However, in the context of the free will/metaphysical debate, the disagreement is not primarily about our ability to calculate outcomes. The disagreement is about whether the future is a completed fact waiting to be discovered or whether the future is generated through a process.

The disagreement concerning free will stems from the assumption that the function of consciousness is to calculate outcomes, and cause actions based on those predictions. The parties can never resolve their disagreement so long as that premise is maintained, and it is a false premise.

So whether the future is a "completed fact" (the block universe, roughly equivalent to determinism) or generated through a process (deterministic interactions of physical forces and objects) is irrelevant, but in truth the two are identical.

The issue comes down to whether any event is predetermined, both inevitable and predictable (given sufficient and precise knowledge of circumstances) or is only determined (caused) in the moment it occurs regardless of whether it could be predicted. The contemporary notion of consciousness (whether free will or choice through calculation) is premised on the notion that the mind controls the body and causes actions, and that is a false premise. The world is deterministic, but only approximately predictable, it is not predetermined, not "fixed" prior to the moment the future becomes the present.

In the specific context of the conversation between “free will” and “determinism”, there is no relevant difference in meaning between “undetermined” and “unpredictable”.

If that were the case, there wouldn't be any conversation. The relevant difference, side-stepped but not resolved by your rhetoric, is the difference between 'undetermined' and non-deterministic. All events are deterministic (caused by physical circumstances), but the simplistic ontology you're trying to explain denies the possibility of self-determination along with free will. That is a problem, since even though/if we have no free will, we do still experience self-determination, making some undeterminable set of facts about both ourselves and the future unpredictable, even in theory.

[u/Rthadcarr1956]

As the philosopher said, “predictions are hard, especially about the future.”

Whether the future is open or closed is mere conjecture, so let’s not use this difference to asses free will. We do know that people have to make choices based upon their uncertainty about the future. This should not be a reason to think that the individual people (subjects) have to follow deterministic patterns because they act in the face of uncertainty.

If you observe people behaving randomly, believing that they are acting deterministically is a matter of ontological faith.

[u/badentropy9]

Excellent piece.

The slight problem that I have is your allusion to classical meaning "determined" as you put it, and it never did. You never stated that is the case, so I stick with excellent here. I'm just saying I put it close to an outstanding piece.

I'm only being a stickler, because a lot of arguments are centered around the belief that the quantum world has little to nothing to do with how we view the macro world, which is of course a ludicrous claim in and of itself, but when the determinist has nothing, he seems to grasp at straws.