Total Eclipse

Today in Metaphysics Lab I had an argument with the tutor against conceivability arguments. It is a common form of argument and phrasing in general in the field of metaphysics to speak of “possible worlds”. This may seem as intuitive as “is it conceivable that there is a logically possible world where I did not wear a black shirt today?” to the stranger “is it conceivable that there is a logically possible world where humans can fly?” or “is it conceivable that there is a logically possible world where water =/ H2O?”
My opposition to this form of language game comes in several phrasings which I believe may in some part be equivalent;

Firstly, I’d argue that anyone (nominally, a Dualist) trying to argue that Metaphysical Conceivability (a “real” possibility, in some sense) follows from Epistemic Conceivability (it’s possible for us to think it) will have a very hard time backing it, without, in turn, using a “possible worlds” form of argument, thus making it circular.

Secondly, I believe that we err in principle when we state that something other than reality is conceivable in the fullest sense. Saying that it is conceivable that Julius Caesar did not cross the Rubicon does not entail that we can truly conceive of a world where this important historic fact did not occur; Can we truly propagate to any degree of accuracy at all what would have followed in history? And what of insignificant historical facts? How do we determine which are significant and which aren’t? I don’t honestly believe it’s possible (or productive). The universe is so immensely complex and chaotic, there is no way for us to propagate even simpler outcomes of different initial conditions, let alone possible worlds where the laws of physics are different, for example. This is known as the butterfly effect, and I’d like to see it used more often to refute conceivability arguments.
Another phrasing; To most, it appears intuitive that we can conceive of logically possible worlds where things would be different, and yet remain identical. That I’m still me in a world where I did not wear a black t-shirt today. To me, this point is completely nontrivial. Saying that there is a possible world where Julius Caesar did not cross the Rubicon presupposes what I believe is a deeply controversial philosophical stance about identity, namely Essentialism (or Realism as opposed to Nominalism). It assumes we can separate the “essential” things which make Caesar “him” from nonessential contingent facts. Facts that just “happened” to be true in our world, but are not in some way unnecessary in other logically possible world.
My position is that a world where Julius Caesar did not cross the Rubicon, is not in any way equivalent to our world. That is not Caesar. In fact, it’s hypothetical nonsense.

What does it even mean to be “logically possible”? Logic is a framework of deductive rules based on empirical observation. Yeah, this one got a big laugh out of class, (bunch of rationalist wankers) but I still believe it is essentially true. Does a man born in a coma know of the law of excluded middle? If he wakes up will he know? Quite the contrary, I believe the position which holds that human deductive rules have some sort of ontological existence outside of human use is the laughable notion. Not to mention, we now know of other logical frameworks (quantum for example) where the law of excluded middle doesn’t even apply.
My main point is thusly so; Without the capacity to distinguish “essential” from “nonessential” properties (and don’t talk to me about “Natural Kinds”), or in the stronger form – from the Nominalist position that no such distinction is possible – we lose any ability to form conceivability arguments. I can just as easily claim (in fact, I think I might just do so), that my wearing a black t-shirt today is a nonredundant (or if you like, necessary) condition in an unnecessary but sufficient chain of conditions which allows the universe to go on. That in some complex metaphysical sense, it is necessary that it be so.
It is only contingent in the sense that it is epistemically conceivable that I would wear another shirt, but in a metaphysical sense we have no way of knowing if it is contingent or not.

Note that hard determinism does not follow from this point of view (as someone in class suggested). I do not claim that our epistemically contingent facts are apriori or that they are epistemically necessary in any way manner or form. Hardly, they are empirical and posteriori by definition. They just may or may not be metaphysically contingent, with no relation to what we can know about them, or conceive.

As an afterthought, I’d like to say that any position which tries to coherently build a concept of Identity which allows for change, need be very careful in how it does so, precisely not to allow absurd arguments such as the “logically possible world” where I am still me, yet I’m a 7-dimensional superintelligent shade of the colour blue. Otherwise, I, for one, would much rather toss the concept of identity out the window and be done with it.

Tagged as butterfly effect, conceivability arguments, dualism, epistemic conceivability, essentialism, identity, logical possibility, logically possible, mere-conceivability, metaphysics, natural kinds, nominalism, realism, שי ברוג + Categorized as Philosophy