I also have read quite a bit of philosophy! So this should be fun to discuss.
First, I agree that 100% certainty is virtually impossible. However, there comes a point when we say we’re “certain”, depending on the severity of the outcome and the probability of it.
For instance, if I offered for you to play a game where we spin a big spinner, and 99.9999999999999% of the wheel is red, which means you pay me ten thousand dollars, and the rest of it means I pay you ten thousand dollars…you’d probably not say “I might win ten thousand dollars!” You’d probably say “this forces me to give you ten thousand dollars”. And if I said “whaaaat, no, we can’t be certain of that!”, you’d probably think I was being nonsensical.
So let’s acknowledge that while Descartes’ arguments for solipsism are indeed basically undefeated on a first order logic basis, we really should be evaluating the claim on a probabilistic or statistical basis instead, since the argument is fundamentally about our degree of sureness in something.
You’re correct that ultimately my senses alone are my only exposure to the world. However, there are some interesting things I can notice. If I lock 1000 people in a room with an undetectable poison gas, then they all will die - even though none of them had any sensory awareness of the gas! If it was just one person in the room, maybe we could argue that reality isn’t consistent, but the fact that all 1000 people due suggests that the gas affects everyone the same consistent way. Similarly, a blood clot in my leg can kill me even if I’m not aware of it.
Acknowledging now that things can certainly affect things regardless of their sensory awareness of each other, the only way to preserve our radical doubt of our senses is to suspect that perhaps the 1000 people in my room are actually not really people, but instead something me and my senses have imagined. If we suppose (against all other evidence, mind you, and purely on the basis of being able to achieve an impossible100% certainty to the contrary), that my senses really do deceive me at every turn, then we have other situations that will puzzle us:
For example, I’m studying math as a 7 year old and coke across a fancy integral equation, which I absolutely cannot make sense of, and I don’t even know what the symbols mean. Later in life, in my 20s, I have learned enough math to understand the equation, and remarkably, I see that it made sense all along. The equation was always right, even before I had the mental capacity to understand it. How could this be, if my perception of the world was not mapping to some consistent reality? These are things that we must come up with strange explanations for, like claiming that my consciousness actually fully understands all workings and states of the universe, and I’m only playing a game with myself where I pretend to forget about it, or something like that.
And if we were to make such a fantastical interpretation for the world as that, what would be our evidence for that interpretation as opposed to the “default” one that the world is self consistent and maps consistently to the our sensory interpretation? Our evidence could only be “we can’t prove with 100% certainty that this isn’t the case”! But if that’s a good reason to believe things, I could just as well say that we can’t prove with 100% certainty that my default interpretation isn’t the case either, and now our claims (and any claim) are on equal footing - since nothing can be 100% certain. All that this really does is show to us that this justification is completely useless, as it makes all claims equally viable and negates itself.
I also have read quite a bit of philosophy! So this should be fun to discuss.
First, I agree that 100% certainty is virtually impossible. However, there comes a point when we say we’re “certain”, depending on the severity of the outcome and the probability of it.
For instance, if I offered for you to play a game where we spin a big spinner, and 99.9999999999999% of the wheel is red, which means you pay me ten thousand dollars, and the rest of it means I pay you ten thousand dollars…you’d probably not say “I might win ten thousand dollars!” You’d probably say “this forces me to give you ten thousand dollars”. And if I said “whaaaat, no, we can’t be certain of that!”, you’d probably think I was being nonsensical.
So let’s acknowledge that while Descartes’ arguments for solipsism are indeed basically undefeated on a first order logic basis, we really should be evaluating the claim on a probabilistic or statistical basis instead, since the argument is fundamentally about our degree of sureness in something.
You’re correct that ultimately my senses alone are my only exposure to the world. However, there are some interesting things I can notice. If I lock 1000 people in a room with an undetectable poison gas, then they all will die - even though none of them had any sensory awareness of the gas! If it was just one person in the room, maybe we could argue that reality isn’t consistent, but the fact that all 1000 people due suggests that the gas affects everyone the same consistent way. Similarly, a blood clot in my leg can kill me even if I’m not aware of it.
Acknowledging now that things can certainly affect things regardless of their sensory awareness of each other, the only way to preserve our radical doubt of our senses is to suspect that perhaps the 1000 people in my room are actually not really people, but instead something me and my senses have imagined. If we suppose (against all other evidence, mind you, and purely on the basis of being able to achieve an impossible100% certainty to the contrary), that my senses really do deceive me at every turn, then we have other situations that will puzzle us:
For example, I’m studying math as a 7 year old and coke across a fancy integral equation, which I absolutely cannot make sense of, and I don’t even know what the symbols mean. Later in life, in my 20s, I have learned enough math to understand the equation, and remarkably, I see that it made sense all along. The equation was always right, even before I had the mental capacity to understand it. How could this be, if my perception of the world was not mapping to some consistent reality? These are things that we must come up with strange explanations for, like claiming that my consciousness actually fully understands all workings and states of the universe, and I’m only playing a game with myself where I pretend to forget about it, or something like that.
And if we were to make such a fantastical interpretation for the world as that, what would be our evidence for that interpretation as opposed to the “default” one that the world is self consistent and maps consistently to the our sensory interpretation? Our evidence could only be “we can’t prove with 100% certainty that this isn’t the case”! But if that’s a good reason to believe things, I could just as well say that we can’t prove with 100% certainty that my default interpretation isn’t the case either, and now our claims (and any claim) are on equal footing - since nothing can be 100% certain. All that this really does is show to us that this justification is completely useless, as it makes all claims equally viable and negates itself.