I'm asking if infinitesimals exist in the sense that would satisfy mathematical platonism. — Michael
Platonism about mathematics (or mathematical platonism) is the metaphysical view that there are abstract mathematical objects whose existence is independent of us and our language, thought, and practices. Just as electrons and planets exist independently of us, so do numbers and sets. And just as statements about electrons and planets are made true or false by the objects with which they are concerned and these objects’ perfectly objective properties, so are statements about numbers and sets. Mathematical truths are therefore discovered, not invented.
Fine! I have realised the link between Terrence Deacon's absentials and the via negativa. Anyway, as you say, enough for today, thanks all for the comments :pray: — Wayfarer
Yep. And to this I would add that the relation between what exists and what we do is worth considering. Language is one of the things we do. Didn't Habermas reflect on this in his use of unavoidability and irreducibility? That it is action that has import?And I don't think the resulting ontological "theory" says that existence is dependent on language — J
:grin: If you like. You insist on telling us, at great length, about the ineffable. Fair enough. I'll continue to point out that you haven't, thereby, said anything.A very shallow analysis — Wayfarer
‘Esse is percipi,’ wrote the empiricist metaphysician George Berkeley around 1710: ‘To be is to be perceived.’ For something to exist or be real, for Berkeley and for many others (Immanuel Kant, for example), was for it to play certain roles in human perception or to correspond to our mental imagery. In a tribute to that style of metaphysics and a parody of it, in 1939 Quine said that ‘to be is to be the value of a variable.’ Now, Quine took himself to be ridiculing the grand pronouncements of metaphysics. But it was hard not to hear that ‘bound variable’ stuff as itself an ontological theory according to which existence is dependent on language: to be was to be picked out by the ‘something’ in sentences like ‘there is something that’s tall and green’ (or, in the language of logic, (∃x)(Fx&Gx), in which the existential quantifier binds the variable ‘x’). — Sartwell, The post-linguistic turn
It's not as if we must choose and stick to only the quantificational interpretation, or alternately we must only ever use the substitutional interpretation. Which we use depends on what we are doing, on the task in hand.I lean toward the quantificational interpretation that allows P to be a "new thing" — J
A misleading phrase, since it implies a background of subjectivity prior to, say, counting; the incoherence of the solipsistic homunculus talking to other homunculi. What is salient is that arithmetic is an interaction between people, and this is so even if one occasionally counts to oneself....intersubjective agreement... — J
A pity then that did not address the argument of my post directly, but instead could only see it as reactionary 'fear of religion'. But yes, it is circular to reason that evolution is needed in order to explain reason. The relevance of that remains obtuse.The only form that genuine reasoning can take consists in seeing the validity of the arguments, in virtue of what they say. — Thomas Nagel op cit
Rather, these CAN be understood as constructs. If you feel you need to include, in addition, a god or a platonic realm or whatever, then that's your choice.these MUST be understood as constructions, hence contingent facts, our own creations, — Wayfarer
This is a good question. What the Fibonacci sequence gives us is a way of talking about the things you picture. It doesn't provide an explanation of why the shell follows that sequence. But it's not hard to find one.How do you apply that to these examples of the Fibonacci sequence? — frank
If the number series is indeed invented, pace Frege, it's easy enough to imagine that early users would then discover that certain numbers -- invented merely for counting purposes -- had the quality of being either odd or even. — J
Infinitesimals exist. They are a higher-order quantification that can itself be quantified. Adding "in the Platonic sense" serves only to confuse what is going on.Do infinitesimals exist (in the platonistic sense)? — Michael
Michael's argument talks about the existence of sentences. Hence it make use of quantification in a second-order language - a language about language. In a first-order language we can make an inference by quantifying over a predication - from f(a) to ∃(x)f(x). In second order logic one might perform a similar operation over a group of predicates. If we have ϕ(f(a)), we can infer ∃Pϕ(P) - if f(a) is ϕ, then something (P, in this case) is ϕ. But at issue here is a choice in how this is to be understood. Is it about just the things (a,b,c...) that make up the domain of the logic, or does it bring something new, P, into the ontology? The first is the substitutional interpretation, the second is the quantificational interpretation. This second interpretation has Platonic overtones, since it seems to invoke the existence of a certain sort of abstract "thing". — Banno
I am inclined to argue that maths do not 'exist' in any objective sense. — Tzeentch
Indeed, I did not address it, becasue I had done so previously. The repetition is tiresome.I explained it quite clearly in my last post here which you opted not to address. — Michael
There's something about the structure of math that matches up to the structure of the universe in some ways. — frank
'Counts as..." doesn't change the words to match the world, but the world to match the words. So "That counts as a duck" makes that thing a duck, an act of intent on the part of the speaker.Maybe this is different, but you have to wonder: does it make sense to talk about something counting as a duck, if you don't know what it means for something to be a duck? — Srap Tasmaner
...that's not taking the "counts as" act seriously. If the tail counts as a leg, that's five.And the answer is: four, because calling a tail a leg doesn't make it a leg. — Srap Tasmaner
Yep.This isn't to say that a duck is a social construction, even though counting as a duck is. — fdrake
But Big Mad H might've been on to something. — fdrake
Roughly, philosophy does the conceptual stuff and psychology does the empirical stuff. Whether we "learn that the practice of counting as", as you ask, seems to me to be an issue for empirical investigation.I suppose we could quibble about the boundary between philosophy, psychology and neurology. — fdrake
i didn't see that in your example. Sure, the paper can count as different things, bitt hat' not different types of counting as...I think they're species of counting as. — fdrake
I take that as a psychological or neurological question. Arguably neural nets are built in order to continue in some pattern - to "predict" is how it is usually phrase.Even to learn that the practice of "counting as"? — fdrake
I'd be happier if you said "...to construct the real"....to create the real. — frank
I do think "where the types come from in nature and norm" is a very different question than "under what conditions are sentences true", and a slightly different question from "where does the correlation between nature types and norm types come in". — fdrake
