RE: Decartes' Substance Dualism
Absolutely! I recently realized a fun argument stemming from these sections of Meditations. If the only thing I can know with absolute certainty is my own existence, and that is a subjective experience, then should we really discount subjective experience as being less descriptive of truth than objective experiences?
Senses fail and dreams can seem real. Hell, we don't even sense the actual thing. As Descartes said, “(when I) see men crossing the square … I normally say that I see the men themselves … Yet do I see any more than hats and coats which could conceal automatons? I judge that they are men.” That is, our minds filter our senses based on past experiences. We cannot trust our senses because all previous experiences could be false (eg., pre-programmed, or experienced only within a simulation).
That's very true: the thing we are most certain about is the thing most impossible to prove objectively. This goes for qualia in general: doctors don't even have a precise objective definition for pain, and usually just have you indicate which emoji printed on a paper describes you more!
I guess the area of phenomenology tries to do what you're saying: put the horse of consciousness back before the cart. But I almost don't know anything about phenomenology so I might be wrong about their intentions.
I guess the reason for not putting consciousness first is because - unless we want public discussion to degenerate back to 'you said VS I said', as is done with religion which leads to fighting and wars - we should only accept as objective truth what can be publicly verified by all. Otherwise what do you say to a person who is quite convinced he is God incarnate?
My own approach to this whole argument that the senses betray us, is to ask "how do you know?", to which the answer is, "well, further inspection by the senses convinces me this is so". So the senses come out back on top.
In other words, I interpret most of these arguments to be of the form: "The senses (in specific occasions) mislead us. Therefore the senses (in toto) cannot be trusted." This is quite uncalled for if you realize that the only reason you know the specific sense impressions are misleading you is because of the senses in toto. The skeptics are, in effect, saying: because the senses (in toto) led me to the truth regarding some cases where I was misled, therefore I cannot trust them. It's like saying "person X showed me I cannot trust person Y, therefore people are not trustworthy". But if you don't trust person X then you don't have any evidence that any person is misleading you. So you need the senses to prove that certain sense impressions are misleading. But if you can prove that, then you can trust the senses.
At any rate, that's the summary of my own pet project in how I intend to deal with this kind of skepticism.
Sorry for the long comment, I tend to be verbose :D
Well, sure, objectivity is the most practical approach, but that doesn't make it the most representative of truth. Similarly, solipsism isn't useful, but is logically sound—or we usually talk about the past and future as actually existing when we can't prove that they are. What this then comes down to is which we value more highly, utility or truth.
Regarding the senses being used to error check the senses, at best we can say that the later sense perception seems more reasonable than the earlier because it is more consistent with what we believe we have previously perceived. The determination is based only on consistency.
If you were to write a piece of code that worked sometimes and not others, you would have to admit that the code is faulty or should be rewritten. You are arguing for writing a second piece of code for finding consistency in the outputs of the first piece of code and then throwing out inconsistent data from the final output. Unless the second chunk is very good you run the risk of undue biases, for example, confirmation bias. For example, both the theist and atheist will remember the experiences that confirm their core belief and forget those which challenge it. The adept programmer would rewrite the first function from scratch to reduce fault points.
Beyond that, there are other means for testing for truth, for examples reason & introspection. Of course, the kicker is that without having boot loaded ourselves based on sense perception experiences early in life, both reason and introspection would have nothing to think about other than the 'I'.
Good reply!
Well I suspect we value believing in other minds and the past and future cos we believe in them, not because there's utility in it. I think we view our inability to disprove solipsism as more of a logical puzzle, like the ones by Zeno of Elea, rather than something to take seriously.
But this just places intuition above logical proof, I guess.