It’s surprising how many people try to suggest that we could have done otherwise (sometimes abbreviated as CHDO online) in an entirely causal (deterministic) universe, when discussing the free will debate. And it’s always surprising how many people don’t recognize the contradiction of such. In my book I point this out with numerous demonstrations, but for this article I just want to get to the vegan-meat and potatoes. First let’s address what we mean by “could have done otherwise”. This statement is not an “after the fact” statement, as obviously once something has been done that is the thing that was done. We are addressing that if we were to somehow bring the moment back to before the decision or action, that such a decision or action doesn’t have to take the same path (it could lead elsewhere). So let’s get into the contradictory nature of such an idea.
The best way to do this is to be as quick and direct as possible:
If a cause (X1) contains the variables that lead to X2, those cannot be the same variables that do not lead to X2.
Think about this, as it’s important. The contradiction should be obvious: to be the causal variables that lead to X2 means that those variables cannot be the same causal variables and not lead to X2, as those two things are in opposition. If causal variables do not lead to X2 (but rather Y2 instead of X2), then they cannot be the same causal variables that lead to X2.
So if you suggest that a cause can be the identical causal variables and the next event could be otherwise, you are either doing one of two things:
1) Asserting a variable with self-contradictory properties
This article will not be going over the problems with acausality (2), or how such events would be even more detrimental to willing than causal events that couldn’t have been otherwise – if they were able to take place . That will be saved for future articles, but if you can’t wait I go over the problems with acausality thoroughly in my book: Breaking the Free Will Illusion. For this article I just want to address a universe where every event (after the big bang – we don’t need to assess prior if there happens to be a “prior”) has a cause.
Which brings us to #1. If the variables are the same, then those variables have self-contradictory properties. But perhaps, you might say, those variables may not be the same. If they are different variables that lead to X2 than the variables that lead to Y2 (if we were to go back to that point), then indeed, they wouldn’t be self-contradictory variables, as we wouldn’t be talking about the same variables for each.
But this is equally as problematic, because the causal variables that lead to X2 must have their own causal variables that led to them (in an entirely causal universe). In other words, if we say that it is the variables within X1 that leads to X2, or variables within Y1 that leads to Y2, we then now have an X1 and Y1 to contend with. We must then ask, what are the causal variables that led to X1 (over Y1) or Y1 (over X1)?
Since there are causal variables that led to X1, for example X0, then it’s equally as contradictory to say that X0 could be the variables that do not lead to X1 (but to Y1 instead). This same problem stems back and back to the big bang. If the initial conditions are the same, and all events are causal, there can be no “different” variables without a contradiction. This means that Y0, Y1, and Y2 are logically impossible happenings in a universe where every event has a cause.
At this point some people jump to quantum mechanics as their escape from this prison. This is where things get sticky for many, and confusions arise that cause people to drink the quantum Koolaid and think that the prison can be escaped. I think it’s more important that people understand the basics above, so if you don’t want to go down the quantum rabbit hole you can stop reading here and just think about the implications of the above.
Still with me? Okay, down the rabbit hole we go!
For some interpretations of quantum mechanics some events do not have a cause, but again, we aren’t addressing those interpretations here (which contain the same acausal problems I will address later). Just know that any acausal events can never be a “willed” event.
There are entirely causal (deterministic) models, and they all fall under the same problem as above (even if some think they do not). Some may however be a little more confusing in how they do this. For example, for some interpretations what is professed is an actual (rather than merely conceptualized) superpositioned state. In other words X1 can lead to both X2 and Y2, both in a superpositioned state. And how they come out of such a state depends on the interpretation as well. A realist view of a many worlds interpretation says that each “decohere” to their own environment (or history, or world, or universe) that is undetectable from each other. But all of this happens causally, and doesn’t escape the problems above. You can think of “decoherence” as a sort of leaking into the environment.
In other words, if X1 leads to a superpositioned state that contains both X2 and Y2, that superpositioned state is the causal result of X1. We can call the superpositioned state that contains both Z2. So the variables that are X1 lead to the superpositioned state of Z2. This means X1 couldn’t have been the variables that do not lead to the superpositioned state of Z2 (which remember, contains both X2 and Y2).
So the event leading to the superpositioned state cannot escape this problem. But neither can the moving out of the superpositioned state into the various environments. This happens entirely causally as well. In other words, the environment or “world” that X2 decoheres to is the world it must, and the world that Y2 decoheres to is the world it must. Otherwise, we are back to either a self-contradiction or the need for an acausal event (that would be entirely out of our control anyway). So the decoherence of X2 into X3/world A1 could not have been otherwise, and the decoherence of Y2 into Y3/world B1 could not have been otherwise. Or to put it another way, on measurement of superpositioned state Z2, such must lead to Z3 (which is X3/A1 and Y3/B1). This does not leap to an “otherwise” ability.
For more problems with many worlds interpretations and free will see here: Many Worlds Away from Free Will!
Quantum mechanics is wacky, strange, and sometimes fun to think about, but it doesn’t, as some seem to suggest, allow for illogical assessments. As soon as we lose logic, we no longer can identify anything. The very mathematics that quantum mechanics are founded on breaks down without such. So don’t believe people that tell you it allows for actual logical contradiction to take place in the world, it doesn’t.
There are other deterministic models of quantum mechanics such as Bohmian mechanics (a nonlocal hidden variable interpretation) and so on, but they all have this very same problem. If entirely causal, they cannot have variables that could lead otherwise than what the very specific structure of those variables dictate. To do so we must abandon logic altogether, which means we can’t even talk about anything as all identity is lost and what we say becomes meaningless.
If the above stuff about causal quantum interpretations seem too confusing, just bring it back to:
If a cause (X1) contains the variables that lead to X2, those cannot be the same variables that do not lead to X2. But those variables cannot be different either, as other causal variables have led to them.
This very same logic applies to every and all deterministic model of quantum mechanics. Later, we will get into why acausality and indeterministic models not only cannot help with free will, but would be entirely detrimental to the ability to “will” if they have any important relation to our thoughts, desires, or actions.