Stanford Encyclopedia : Perception
Wikipedia : Direct and Indirect Realism
On various philosophy forums I've participated on, there have been arguments between those who call themselves 'direct realists' and those who call themselves 'indirect realists'. The question is apparently about perception. Do we experience reality directly, or do we experience it indirectly?
When I was first initiated to the conversation, I immediately took the indirect side -- There is a ball, photons bounce off the ball, the frequency of those photons is changed by some properties of the ball, the photons hit my retina activating light-sensitive cells, those cells send signals to my brain communicating that they were activated, the signals make it to the visual cortex and...you know...some stuff happens, and I experience the sight of a ball.
So, my first thought in the conversation about Indirect vs Direct realism was that there was a lot of stuff in between the ball and my experience of it, so, it must be indirect.
But then I found that direct realists don't actually disagree about any part of that sequence of events I described above. For them as well, at least the few that have bothered to respond, photons bounce off a ball, interact with our retinas, send signals to the brain, etc. The physical process is apparently the same for both sides of the debate.
And when two sides vehemently disagree on something, and then when the question is broken down into easy, answerable questions you find that they actually agree on every relevant question, that tends to be a pretty good hint that it's a wrong question.
So, is this a wrong question? Is this just a debate about definitions? Is it a semantic argument, or is there a meaningful difference between Direct and Indirect Realism? In the paraphrased words of Eliezer, "Is there any way-the-world-could-be—any state of affairs—that corresponds to Direct Realism being true, or Indirect Realism being true?"
Hey, thanks yourself for responding in such depth. I didn't mean to imply that I was agreeing completely with ShiftedShapes, or disagreeing completely with you. I'm afraid my last post was a little rushed because I had to leave for work, so there are a few errors and I wasn't as clear as I would have liked. I definitely agree with your points about the importance of perspective - I think the perspective we should consider here is that of the human condition: what Heidegger would have called Dasein.
In that case, I think the uncertainty that stems from differing perspectives is tangential to the problem at hand. ShiftedShapes said:
It sounds like all three of us agree with the first part of that statement, since the content of experience is contingent on dasein. I want to make the case, though, that experience itself is neither "certain to exist", nor "uncertain to exist". I think that "experience itself" is fundamental to dasein, and that therefore cannot be subject to either certainty nor uncertainty. I think the existence of experience is what Wittgenstein would have called a hinge proposition: one of the propositions which constitute the frame of our perspective, which we use to form the question of whether or not a given proposition is certain or not.
As you rightly point out, there is a close parallel here to axiomatic logic. That said, I'm not suggesting that "experience exists" is merely an axiom, because although axioms do help to define the frame of a system, they're still sometimes contingent and so we can sometimes still talk of their certainty or uncertainty. Famously, Euclid's fifth axiom, the Parallel Postulate, can either be affirmed or denied to create different geometries. It's important to note, though, that an axiom of any particular system can't be proven from within that system, any more than Baron Munchausen could pick himself up by his own bootlaces. If "experience itself" really is a fundamental element of dasein, then, we can think of it as an axiom of the human condition. Since we can only observe from within the human condition, this places the question of the existence of experience beyond proof or disproof, beyond contingency, and therefore beyond certainty or uncertainty.
I also believe that there are many things that we would agree on; my arguments are just an indication that I currently find certain aspects of this topic interesting to argue about--mind expanding. :)
I am happy to hold my arguments against certainty for shiftedShapes--however I will... (read more)