On Gangadean's proof of the External World.

In his book, Philosophical Foundation, Gangadean offers a series of arguments where he purports to prove various things that skeptics have historically called into question. Now it's important to keep in mind that 'skepticism' doesn't really refer to a singular worldview. There are many kinds of skepticism. One kind of skeptic, Descartes and those inspiried by him, suggest that our best evidence doesn't rule out the possibility (as remote as it may be) that there is no mind independent reality. By mind independent reality, I mean a real world, "out there" if you will, that isn't merely a fragment of our imaginations like a dream or matrix-like scenario. So Descartes suggested that in light of our best evidence, we can't rule out the possibility that we might be imagining everything that we think we interact with each day. Another way of putting it is to suggest that were the world not actually real (but merely a figment of my imagination) all of my beliefs/evidence would look exactly the same to me as it does now (presumably where the world is real). And since I can't tell the difference between the two, I don't can't rule out the possibility that it is all a fiction.

Importantly, to entertain such doubts or even to take them seriously is not the same as believing that there is no mind independent reality. Descartes didn't believe that an evil demon was causing him to see a world that didn't actually exist. He just wondered how he could tell the difference. In other words he was pointing out that our evidence for claims like "there exists a mind-independent world" is at least inconclusive (leaves room for doubt or to use Gangadean's words, "is unclear") and at worst, non existent (i.e., whatever evidence we thought we for the belief in an external world is equally evidence for a matrix-like scenario).

Philosophers have taken various lessons from such considerations. One view is to consider Descartes' presuppositions. Descartes seems to assume that in order for us to be justified in believing in the external world, we need to be able to tell the difference between the kind of mental states we would be in in the real-world vs. the mental states we would be in in a matrix-like scenario. But some philosophers call this into question. They think that one's belief in the external world can be warranted or justified simply in virtue of the fact that the belief is caused in the right way by the external world. It doesn't matter that you can't prove that your beliefs are caused in the right sort of way. All that is required is that one's belief actually be caused in the right way (i.e., by the proper environment). Indeed one can even know that the external world exists so long as things have gone correctly. These philosophers think that Descartes' worries are actually about whether one can know that one knows that the external world exists and they insist that we needn't worry about knowing that we know things. Some philosophers think that belief in the external world is basic--that is, it enjoys a special epistemic status of being entitled/warranted/justified in virtue of the kind of belief it is. So it doesn't matter that we don't have evidence for our belief in the external world, because it doesn't need evidence to be justified or warranted.

Gangadean on the other hand attempts to prove definitely that there is no rational room for doubting the existence of the external world. Here is the argument.

1) The cause of what I see is either in my mind, in another mind or outside of all minds. 

2) If the cause of what I see is in my mind, then I should have complete control over anything I see. 

3) If the cause of what I see is in another mind, then I should have no control over what I see. 

4) It is not the case that I have complete control over everything I see nor is it the case that I have no control over what I see (that is, I have some control over what I see, but not total). 

5) Thus, the cause of what I see is neither in my mind, nor in another mind. 

6) Ergo, the cause of what I see is outside of all minds.

Gangadean claims that his proof is sound. Now a sound argument should be deductively valid (the conclusion must necessarily follow from the premises) and also must contain only true premises. No doubt it's valid, but a valid argument is not hard to come by. The real test of an argument of this sort is whether or not all the premises are uncontroversial. In this case, they are not.

The main issue with the above argument is that it takes for granted the claim that one can know infallibly whether or not (and to what extent) one is in control of what one perceives. The whole argument rests on this assumption. Notice how premise 4) simply asserts that I do not have complete control over what I perceive.  This assumes that Gangadean can tell whether or not he is in control of what he perceives. But how does Gangadean know that? Once again, Gangadean seems to be appealing to intuitions, here. He takes it that he can just immediately apprehend that he does not have complete control over what he perceives. Further, he thinks he can distinguish between having full, partial, and no control over what he perceives. Of course, he's counting on his own judgment to be infallible here. But how can he trust his judgment like that? For all he knows, it could merely seem to him as if he has only some control over what he sees. But I wonder how he can rule out the possibility that he's wrong. Maybe he has no control over what he perceives. Or maybe he has total control over what he sees despite it seeming to him to the contrary. The question is how he could know the difference? So before this argument can get off the ground, he needs to first articulate and rationally support his method for determining whether or not he's got partial control, full control, and/or no control over what he perceives. Otherwise, the argument above is a non-starter. I have no idea what such a method would be other than introspection. But how can we trust introspection to that extent? How can we know with certainty that introspection is infallible? It all smells of intuitions to me.

A second problem is that premise 2) is also far from obvious. Gangadean needs to argue for this premise. He needs to prove beyond any doubt, how, if our perceptions were the result of our minds, we would have full control over what we perceive. And I just don't see how the consequent follows from the antecedent. Indeed, I spoke with Gangadean once about this. I was reading Descartes at the time and noticed that in his Meditations he mentions in passing the remote possible that all his perceptions/experiences are caused by a faculty in his mind of which he was unaware. Similarly, it's at least possible that our minds are responsible for all that we see, despite our not having control over what we perceive. This would just mean we don't have any actual control (even if it seems/feels to us as if we have some control) over what we perceive.

As I recall, Gangadean admitted that he hadn't given this issue consideration before. Unfortunately he never gave me a fully satisfactory account. His initial response was that admitting to there being such a faculty, would be admitting to the mind being divisible. But it was his view that minds were indivisible, necessarily. But that doesn't count as any proof of anything. First of all, where is the argument that minds are necessarily, indivisible? That's a very substantive claim about the nature of minds, but from what I gather he just took it for granted (perhaps again on an intuition).

Further, to admit to various faculties of the mind is not to admit to the mind being divisible in the first place. 'Faculty' might simply refer to various processes that are instantiated by the mind, like memory, reasoning, executive function and the like. Admitting that the mind is comprised, in someway, of a faculty that is responsible for all our perceptions doesn't imply that the mind is divisible anymore than admitting that the mind consists of a memorial faculty. In other words, 'faculty' as I am using it, is really just a stand-in for picking out particular kinds of mental processes that seem distinct. So the suggestion on the table is that it's at least possible that I am in someway the cause of what I see, despite being unaware of this. The main point is that Gangadean has taken great liberties to make strong claims about the nature of minds. But he can't just state them because they feel right to him. He shouldn't just insist that minds are indivisible. He shouldn't just insist that thinking of minds as consisting of various faculties implies that the mind is divisible. Likewise he shouldn't simply insist that he knows whether or not he's got only partial control over his perceptions. These crucial premises, suppressed as they are in his argument, need to be proven prior to his proof for the external world. Until that day, Gangadean hasn't proven the existence of the external world which means (on his definition of knowledge) he doesn't know there's an external world.

This has major implications for his worldview. For one thing, on his view, creation is supposed to be revelation. We are to know about God on the basis of knowing about creation. But the way that Gangadean has set things up, we can't even know that the external world exists, let alone derive true facts about it.

Now the correct response to these considerations, from my perspective, is not to doubt the existence of the external world.  It's to reject the assumptions that got us into this pickle in the first place and that is to reject the kind of proof that Gangadean demands for rational belief and knowledge. We don't have a proof that the external world exists (just like we don't have a proof for the vast majority of what we believe and take ourselves to know). But this is no impediment to knowledge---it doesn't mean the skeptic wins. We know lots of things because knowledge doesn't require absolute certainty to begin with. Of course, this option is not open to Gangadean and his followers. Skepticism seems the only road for them.