Our third axiom was that people communicate. This is really not a very precise statement for a number of reasons. To communicate seems to imply community- we need a recipient and a communicator. We might be tempted to say that built into that axiom is the assumption that other people exist. Built into that might be the assumption that a world beyond ourselves exists. But for anyone who knows anything about the history of philosophy since the Enlightenment, these assumptions would be unacceptable because one of the principle questions since Descartes has been “on what basis can we claim to know anything beyond myself?”
Here is a whirlwind history of Modern Philosophy based on that question:
Rene Descartes marks the starting point of Modern Philosophy. He argues that we can, via rational argument, move from a starting point of certain knowledge- that I exist- to the existence of everything else. We can construct rational arguments that establish with certainty the existence of the material, external world and other persons with whom we communicate. The problem is Descartes reasoning is circular and therefore few have accepted his conclusions.
Baruch Spinoza follows Descartes in claiming that we come to our knowledge via rational arguments. But he modifies the conclusion a bit: we don’t have knowledge of a world of matter existing outside our minds, we have knowledge of a world of ideas in our minds (think the Matrix).
John Locke isn’t satisfied with Descartes. He thinks we come to all our knowledge not by reasoning but through our empirical/sensory experiences. It is through those experiences that we really do know the external, material world.
George Berkeley offers a critique of Locke that ends up with a similar conclusion as that of Spinoza: our experience doesn’t show us an external, material world, it shows us a world of ideas.
David Hume critiques this entire project by claiming that the categories necessary for us to put together our knowledge of the world cannot be demonstrated either rationally or empirically. Therefore, we cannot know anything.
Immanuel Kant responds to Hume by acknowledging that the categories cannot be demonstrated empirically to exist beyond our minds but then claims that they are part of our subjective experience: we understand the world through the grid our minds create using these categories.
Now, this whirlwind tour is based on a rigorously academic method called “squinting” (technical term given by Miroslav Volf). There are a lot of details left out of this story and that’s because for our purposes right now the details aren’t as significant.
There are just a couple of things that I want to draw attention to.
First, I want to note the back and forth between realism and idealism that happens in this history: the claim that we can really, with certainty, know what the material, external world is like using a particular method gives way each time to a weaker claim- we can know a world of ideas through that method. Both Spinoza and Berkeley want to argue that this world of ideas is the real world, but with Kant we get a change: the world of ideas that our minds put together is not the same world as the external world that exists beyond us. The difference between the two creates a transcendental divide between our experience and reality: we always know our experience, we do not know the world beyond our experience. This has essentially gotten us back to the first axiom.
Second, I want to notice what Kant suggests about the categories through which we understand the world. First I have to acknowledge that there are some differences of interpretation here. Some of Kant’s followers, such as Hegel and many of a more analytic persuasion, want to extract from Kant a way of knowing what the real world is: Hegel by means of an idealism not entirely unlike that of Spinoza or Berkeley (at least on my best attempt at reading Hegel, who is a strong contender for most confusing philosopher ever), others by means of something like what Locke and Descartes wanted to do before Hume got to them. I think in both of these cases that the project is headed in the wrong direction and the essential insight Kant gives us has been missed, the first axiom ignored or overlooked.
Perhaps this misunderstanding is because on the basis of that axiom it does not really seem like we can know anything- my first person experience could be a complete illusion, like Descartes feared. If I am only able to know my first person experience, how will I ever escape the possibility that it is an illusion?
I think what Kant says about the categories is actually extremely helpful in answering that question. What Kant suggests is that we cannot operate in a world in which that possibility is true. In other words, there are some beliefs that are so central to our understanding of the world that we have to accept them even if there is no definitive (or empirical) proof of their being true. By writing his Meditations, Descartes betrays that he believes an external world exists that contains people who can understand what he wrote. He may hypothetically call that world into doubt, but he has not really doubted it so long as he continues to write for it. That Hume picks up a pen to write his critique of causation betrays that he actually believes in causes, else why does he think that the ink will actually reach the page? The point is not that such assumptions invalidate their arguments about our hypothetical doubt of these things. The point is to give credence to the idea that we simply cannot do anything without these assumptions being present.
The conclusion of this is that while we are viewing the world subjectively, from a first person perspective that could in fact be an illusion, the possibility of it being an illusion, the possibility of it being completely false, is one that we need not entertain seriously. There are certain beliefs, beliefs we might call basic beliefs, that are so central to our understanding of the world that we simply must believe them if we want to make sense of anything else. So our third axiom can stand- we can believe that there is a world beyond us and that it contains people with whom we communicate because without such beliefs we simply cannot make sense of anything in the world. It will be up to a later post to explore a bit more what the third axiom might imply and how we might use it.