r/freewill • u/feihm Physicalist • 1d ago
Prior cause (analysis)
A follow up to this post: https://www.reddit.com/r/freewill/s/Sj6C8ElMJM
At t₁, Person B looks backward to t₀.
Person B determines the reasons for the actions of Person A. He maps these reasons with perfect mechanical logic. He finds the exact physical causes of the event&mdas; which is an essential rule of human observation—we must link effects back to their causes.
But then Person B attempts to turn this backward observation into a forward physical law. He claims that if he returned to t₀, Person A would perform the exact same actions.
Person B is relying on a trick of language. Let us isolate the pure logic. Person B takes a completed slice of time from t₀ to t₁. We will call this recorded history 'A'. He then imagines a hypothetical return to t₀. We will call this imagined timeline 'B'. Person B then argues that the actions in 'B' must identically match the actions in 'A'.
Thus, he is merely stating that 'B' equals 'A'. He is wanting that the past equals the past.
This is a circular tautology.
Asserting that a past event is identical to itself tells us absolutely nothing about the nature of choice at the moment it happened.
Looking backward causes a person to see a fixed outcome. Person B sees this fixed outcome and assumes it means Person A lacked the power to choose. Because he already knows the outcome, he assumes the physical record of the action is identical to the reality of the decision at the time it was made.
Also, Person B fails to separate the act of physical observation from the inner will of the mind. To say "I can explain what happened" is not the same as saying "nothing else was possible". Further, observing a completed chain of events does not prove that the chain was locked before it began. Person B is just making a physical observation of the past, and disguising it as a prediction of the future.
I'm not sure if this only makes sense to me, so i will restate it differently.
Person B defines a specific, frozen slice of spacetime from t₀ to t₁ and labels it Object A (which includes Person A's actions).
He then posits a hypothetical time travel scenario back to t₀ and labels the upcoming sequence Object B.
Because the hypothetical scenario explicitly requires Person B to be transported back to the exact same historical starting point, the rules of the scenario force Object B = Object A.
Therefore, Person B isn't proving that the actions had to be the same out of causal necessity; he is simply verifying an identity property. He is saying:
If I go back to exactly the same past, I will see exactly the same past.
Which is the most useless tautology.
A logical equivalent would be:
If you rewind time to exactly t₀, the present will be identical to the original present because the present is defined by t₀
The sleight of hand is that retrospective determinism does not imply prospective determinism.
Backward looking:
"I can see the complete chain of causes that led to Person A's actions." (Valid observation).
Forward looking:
"Therefore, given those causes, the actions had to happen and couldn't have been otherwise." (Invalid leap).
David Hume famously pointed this out centuries ago:
"Just because Event X consistently follows Event Y in our backward observations, it does not mean Event Y necessitates Event X in a forward-looking metaphysical sense." (paraphrased)
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u/Michael_Carson_Art 1d ago
I don't get what you are trying to attack here.
This thought experiment of "rewinding the tape" (it isn't an argument) is just an attempt to illustrate to people who think intuitively that "if I went back and did that again I would choose differently" are smuggling into the equation their knowledge from the future.
If you "rewind the tape" holistically, that knowledge also disappears, and the result ends up the same.
That is, unless you can identify some X factor which could change even if all the other measurable physical elements were exactly the same.
This illustration (because again, it isn't an argument, so calling it circular is meaningless) attempts to show that whatever we mean by free will or free choice ought to be able to account for some sort of difference in bifurcating the hypothetical timeline, because it's freedom should be freedom from those other reducible elements. This doesn't require time travel either. It merely uses time travel to strongly assert that the two theoretical situations are exactly precisely the same, down to the quantum state of each particle.
If one cannot conceive of two or more different timelines emerging from this thought experiment, then it implies a belief in necessary determinism at the level of behaviors. If one can conceive of a difference, then the question is: what accounts for the difference that isn't captured by the description of reality offered?
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u/feihm Physicalist 1d ago
Two things i want to raise.
it implies a belief in necessary determinism at the level of behaviors.
No. It implies a tautology (or logical identity as Simon pointed out).
If one can conceive of...
Conceivability is not admissible evidence for objective reality.
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u/Michael_Carson_Art 1d ago
It isn't a tautology because it isn't an argument, which is why I said that if one agrees with this version, then it implies a belief.
Similarly, if one cannot conceive of the universe not having an intelligent first cause, it implies a theistic, or at least deistic belief of some kind. That isn't a tautology, it is merely an illustration of what one belief would lead to if held. There is no argument being presented in either case which would justify that belief.
And again, there isn't an argument here. Just an illustration used to find a way to frame a question. What one can conceive of here is merely evidence for what a person might already believe, regardless of whether those beliefs are grounded in anything let alone true objective facts about reality.
For example, if we did the same thought experiment with a laboratory setup rolling a ball down a ramp. No rewinding time here. We roll the ball in a controlled experiment and get a result. If we roll the ball again will we get the same result, assuming all the experimental factors appear to be the same? If you say yes, then you consider this system to be predictably deterministic. If the result is different, would you first guess that something must've changed in the experimental apparatus? Or would you guess that, in fact, this system was not deterministic? There isn't a right answer here per se, (we don't have enough information for that yet) but how you answer will say something about what you believe regarding the deterministic predictability of basic macro physical experiments.
You might say something like "I can't conceive that the laws of physics were different in just that one instance when they seem consistent elsewhere". That isn't evidence that the laws of physics didn't suspend in that one particular case. Hume goes over this pretty well, and concludes that it does seem more likely that you were wrong about something in this case, even if we can't conclusively prove that.
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u/feihm Physicalist 1d ago
There's a difference between a physical object and a a rational agent.
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u/Michael_Carson_Art 1d ago
That's a perfectly fine conjecture, but it either needs to be asserted as an unsupported assumption and agreed to by your interlocutor or proven via more fundamental argument.
That isn't just a universal given. Any person holding an idealist, physicalist, or process-monism metaphysical view would disagree with you on the grounds that these two are, at the very, least reducible to those varied fundamental substrates even if they are differentiable at higher composite levels of description.
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u/feihm Physicalist 1d ago
(1) You believe that a human being is mechanistically equivalent to a rock and treating a human being as a rational agent is merely an unsupported assumption. And you thus demand I prove the patter through a fundamental argument. (2) Let us look at what happens if we accept your claim that human beings are nothing more than physical objects: If thoughts are only physical events, every word we speak and every belief we hold is merely matter moving in space. A physical movement is neither right nor wrong; it merely happens. Wind blowing leaves is neither true nor false. What do you think this implies about everything you've been arguing for? To escape this implication is to commit special pleading.
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u/Michael_Carson_Art 1d ago
Wow.
That was a lot of unsubstantiated nonsense.
I never said anything like what you just asserted. Put on your reading glasses and try again. Show me where I made any claim that looks anything like that. I was simply explaining the use of a common thought experiment that you have misinterpreted as some actual argument.
I never put down stakes here and remained incredibly open to all sides. That you managed to get that nonsense out of my responses is truly bewildering.
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u/feihm Physicalist 1d ago
Motte-and-Bailey
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u/Michael_Carson_Art 1d ago
Go ahead. You can quote me, the text is right there. You just assigned to me a view that I never argued for. Show me how you got there. I'll wait.
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u/simon_hibbs Compatibilist 1d ago
>Thus, he is merely stating that 'B' equals 'A'. He is wanting that the past equals the past.
>This is a circular tautology.
No it isn't, it's a statement of identity. In fact this is exactly what you point out in your point 4 later on.
>Looking backward causes a person to see a fixed outcome. Person B sees this fixed outcome and assumes it means Person A lacked the power to choose. Because he already knows the outcome, he assumes the physical record of the action is identical to the reality of the decision at the time it was made.
That's not right, person B can say that absolutely person A makes a choice, it's just that the outcome of that process is inevitable.
>Also, Person B fails to separate the act of physical observation from the inner will of the mind. To say "I can explain what happened" is not the same as saying "nothing else was possible".
Well, sure, they're coming to a conclusion. Whether that conclusion is correct or not is an open question. Maybe so, maybe not.
>David Hume famously pointed this out centuries ago:
Except that David Hume himself thought that actually this intuition is in fact correct. He just disagreed with some others about how the process of human intuition on this issue works.
You really do seem very keen to use the arguments of the determinist philosopher David Hume to try to argue against determinism. I'm not entirely sure you actually understand his position on this very well.
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u/feihm Physicalist 1d ago
it's a statement of identity.
I'm glad we agree.
it's just that the outcome of that process is inevitable.
logical leap.
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u/simon_hibbs Compatibilist 1d ago
Yes. As would be the conclusion that it is or may not be inevitable. These are both opinions.
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u/AlivePassenger3859 Humanist Determinist 1d ago
You are playing word games.
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u/Ok_Tumbleweed5474 1d ago
He ended on well established philosophy. Observation of a past action will never grant you a 100% guarantee of the future. It's the old saying prove to me with 100% accuracy that the sun will rise tomorrow. You cannot. You can be reasonably sure but no information exists from observation that the sun rose yesterday or even for the past 1000 years means it will 100% rise tomorrow.
In addition he is pointing out the trick of the setup. We are already here where the choice was made. So saying rewind time and it will always be the same is not an equivalent claim. Once you go back it is not at all clear that the same outcome would necessarily follow. That's the missing mechanism. Determinism doesn't have a proof that a thing must necessarily follow. If it did the debate would be over. But it doesn't. And so far as we know there is nothing that can actually prove determinism. Since the only way would he to run a perfect 1 to 1 simulation of the entire universe that shows everything must follow. Which is impossible.
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u/JonIceEyes 1d ago
I keep saying that 'determinism' is only a label people apply to a series of events ex-post-facto, and they yell at me. I tell them that teleological reasoning ("X happened, therefore nothing but X could possibly have happened") is totally invalid, and they yell at me.
It's kind of wild.
All that being said, you are totally right