We use logic to connect propositions, but without the senses are there any propositions that can be known? The self maybe? I’m not sure. Also to verify the fact that logic works we need our senses. I am not confident that a brain without senses could derive logic, and instead it makes more sense to me that logic is a derivation from the way our universe happens to behave.
Connecting this to math, if our universe didn’t have discrete objects like apples, or rocks, and was instead one continuous fluid, would the natural numbers have been created?
Let me know your guys’ thoughts or add to what I’ve said. I’m new here and just want to get some conversations started.
A universe of one continuous fluid wouldn’t be ‘our universe’. It is highly questionable that our universe is responsible for the creation of the natural numbers, but you’re probably talking about the concept of the natural numbers, in which case there’d be no conceiving going on in the alternate fluid universe.
I cannot see how anything, ‘self’ included, would arise from complete sensory deprivation. Sure, the non-sensing entity can get pre-loaded with intuitions and initial state, and it can proceed from there. Even with the senses, one can never know if the sensory stream isn’t all lies.
Responding to your second paragraph: That is kind of my point. I am not arguing that the senses are reliable but to verify the fact that logic works, or to have any proposition to use logic on the senses seem necessary. My overall point from this being that I don’t think logic is foundational as a way to derive truth, and instead it can only really come from the senses.
Interesting OP. It touches on all sorts of deep questions.
So I’m wondering what it would mean to say that logic is a foundational way to derive truth. It seems like you are saying that if logic were a foundational way to derive truth, then truth would not come from the senses. But suppose someone said, “I don’t think the senses are foundational as a way to derive truth, and instead it can only really come from logic.” They might say that animals have senses but not logic, and that animals don’t have truth. For example, animals don’t work out mathematical theorems.
I understand your concern, and what I meant by that last sentence is not that truth can’t be discovered through logic, but that logic is a derivation from the senses, and acts as a shortcut. What I’m really questioning is whether there are truths that could only be known via logic, assuming sensual omnipresence because of course if you say the 6th planet from the sun is a gas giant and you say the 6th planet from the sun is Saturn then you can derive through logic that Saturn is a gas giant even if you don’t have the technology to observe Saturn to see its a gas giant. I hope this clears it up a little but feel free to keep asking questions!
First of all, you still seem to be taking an epistemic approach. Knowledge of logic is likely prior to knowledge of truth, if such a thing can be known at all. Since mental abilities seems to be necessary for knowledge of logic, then knowledge of logic is not foundational.
But do not confuse this with logic itself not being foundational. That hasn’t been shown at all since it really hasn’t even been referenced.
2+3 adding up to 5 seems to be an example of a mathematical (part of logic) truth, but I seriously doubt that any mind would come up with that in the absence of sensory input. Such a thing would not likely be fit in any way and wouldn’t even exist.
I can think of very few non-relational truths besides examples like that one. Your Saturn example is one of a relational truth, something empirically meaningful to us, but not necessarily to others. For instance, ‘the sun’ has no objective meaning. This is harping on ‘truth’ more than it is addressing the logical connection, but absent sensory input, none of the statements you mention would be meaningful. Knowledge of logic is mostly learned, but despite the lack of the formality of it, lots of thinking things wield it, some intuitively. They don’t care about Saturn.
I notice that whilst ‘nominalism’ is in the thread title, it is not mentioned at all in the OP nor the ensuing conversation. What bearing does it have?
Yes, 59, but still completed many important works when blind. Obviously he could hear and dictate his work but the basic point is that mathematics is primarily intellectual in nature - the intellectual perception of values and relations.
Is anyone saying that? Your use of ‘before’ makes it sound like some say that mathematical truths are temporal in nature, true at one time and not true at another, which would make mathematics a property of only this universe.
Wayfarer might say that, but only because he doesn’t distinguish mathematics from the concept of mathematics.
Not that it is related but Beethoven could compose music when deaf. Importantly he could hear music in his head when he read orchestral scores. I have a friend who can do this, he can see a full score and hear what it will orchestra might play; multiple instruments at once just as scored. Not sure what that says about the human mind. Well, some minds.
It would seem obvious that such truths are in no way a function of anything’s sensory input. A rock arguably has no sensory input, and yet 2 wet rocks and 3 dry ones total 5 rocks.
An idealist might argue otherwise since mind is fundamental, everything (including mathematical truths) are no more than mental concepts, and absent sensory input, an idealistic mind would create nothing. Something like that. I don’t speak for the idealists, even if I think some things deemed ‘metaphysical’ are actually no more than concepts.
It is worth pointing out that there is a difference between a proposition’s being true, and a proposition’s being known. This is a core bit of reasoning that tends to go missing as soon as folk start to philosophise.
What follows is that there can be propositions that are true, yet not known.
The implications are considerable. For one, in your fluid universe, it would still be true that 1+1=2, but perhaps the inhabitants would not know this to be so.
Thank you, it’s great to be here. The main thing I was trying to get at with the statement was basically questioning whether logic could actually be used without the senses, but I understand what you are saying.
