Live data from Hacker News

Intuitionism

en.wikipedia.org

141–150 of 179 posts

Re: Intuitionism

#141
post #2

I have liked intuitionism from the very moment I first heard about it. I often entertain the idea that all the patterns we observe are merely things that match our capability of understanding. This could explain the "unreasonable effectiveness of mathematics in the natural sciences". It may also help to guide us away from the "why is there something rather than nothing" problem. If existence is total chaos, then we a…

Isn't this just the anthropic principle from a different angle?

Re: Intuitionism

#142

Earlier quoted context omitted.

Well, we try to discover math. That’s straight forward?

Again, definitional issues are critical here. I can make up all sorts of math that isn't really "discovered", it's more "invented". Most of it won't correspond usefully to the physical universe. See e.g.: https://plato.stanford.edu/entries/formalism-mathematics/ : > "mathematics is not a body of propositions representing an abstract sector of reality but is much more akin to a game, bringing with it no more commitmen…

Take the brevity as a lack of hubris. The notion that “the world is made of math” is one of the oldest and most influential ideas of all time. If you find Pythagoras, Plato and Newton a little incoherent, that’s not unusual. But the onus doesn’t lie with them (or me). In any case, I remain interested in your ideas!

Re: Intuitionism

#143
post #139

The older I get the more I feel like pursuing these trains of thought will lead to mental instability and sadness. We model the world and the world follows the model and the exceptions add to our refinement of the model and that’s what makes it true. Perception and reality are yin and yang and that is about as deep as my philosophy needs to go here

I started being much happier about philosophy in general once I realized a very important truth: "unlike hard sciences, philosophy only affects philosophers" For example the toplevel article says things like "independent existence in an objective reality".. this sounds important, right? Perhaps depending on the truth of the intuitionism, we might discover some facts about real world? Nope. The whole "is intuitionism…

Intuitionism has had a great impact on computer science and the design of many programming languages.

It's now widely known that an intuitionistic proof has computational content (through the curry-howard correspondence)

Those things have a real world impact

Re: Intuitionism

#144

>mathematics is considered to be purely the result of the constructive mental activity of humans rather than the discovery of fundamental principles claimed to exist in an objective reality In the context of the Godel Incompleteness Theorem I have always found it difficult to reconcile mathematics w/ an objective reality. A mathematical system would simply be incapable of completely encompassing objective reality.

What is the opposite of an objective reality?

I don’t know, but an objective reality could exist without it being fully accessible to us or directly corresponding to our mathematical systems.

I guess the opposite would be something like solipsism though.

Re: Intuitionism

#145

This is post-modernism applied to math. It concludes in solipsism. Since the mind and its mental constructs are a part of the objective reality, they will end up describing aspects of objective reality. If they don't, they break down, become chaotic and incomprehensible to those grounded in the objective reality.

I was initially surprised to read this because when I hear Intuitionism, I hear Intuitionist Logic. But IL doesn't have anything to do with denying objective reality; it can use facts on the way to proof. So I don't really know why Intuitionism is so much more adamant about denying constructive reality, or why it's thought to "give rise" to Intuitionist Logic, which at this point seems like a totally different thing.…

If there is an independent source of truth (external reality), then classical logic makes sense and intuitionistic logic doesn't. But intuitionists say mathematics, unlike the physical would, doesn't have such an independent reality. There is no platonic mathematical reality apart from explicit mathematical construction. Then classical logic is inappropriate and intuitionistic logic has to be used for mathematics.

Re: Intuitionism

#146

Earlier quoted context omitted.

The offer of 'objective reality' as the antithesis to solipsistic mental constructs is exactly the naivety that give both of these impotent families of epistemology any continued sway. Both bad, both wrong, and the crowd swings from one to the other, and at each arrival, anew recognizes the flaws of the mode and turns back.

Thank god a philosopher has arrived to tell us we're all wrong. Being so wise, you must have the correct answer for us. What's it going to be today "you're not smart enough to understand my genius solution" or "enlightenment can't be taught, only achieved"?

Yeah. There are some approaches in philosophy of mathematics which try to avoid platonism (the view that mathematical objects have a mind independent existence) but while also retaining classical logic. That's not easily done though. (Currently popular is "structuralism", but this theory has its own problems.)

Re: Intuitionism

#147
post #119

Earlier quoted context omitted.

> mustn't this in turn depend on some pre-existing regularity (i.e. order) in the universe? Yes. And such order exists within the observer, the mediators. We are measuring instruments. Scales are bound to the ruler and not to what’s being ruled. So mathematics represents order only in as much as there are people to validate it. Should all rulers be broken and forgotten, then there’s no measure at all. This is the sam…

Does your "principle which allows order" presume the existence of space and time, and more specifically the ordering of time? I would say that in a universe without time, "cause and effect" have little meaning. I think I lost your train of thought when you say that numbers are qualities of Unit. Does your universe involve only "Unit", or are there other principles at play as well?

The Peano arithmetic hints at the proposition that numbers are gradations within a unified principle, in this case the principle of “succession”. If you start with nothing (zero) and recursively apply the same quality (succession) you get all integers. So we can rationally assume that all numbers are different qualifications of some primitive. As for time and space, they do not fundamentally exist and they do not configure a necessity within the universe. It takes a being able to record and internally persist events for time to appear. Space is similar, being also a referentiality. In essence, time and space are different framings of the same phenomenon. The length distance between two points is also a temporal ratio between the points. It is just two perceptions, two expediences, not grounded in singular reality. I believe “beings” are Unit juxtaposed over Unit, in the spirit of Wheeler ideas [1]. I don’t think there are fundamental necessities other than Unit. Unit is not causality, I have just used the terms for illustration. If there are other fundamental necessities other than Unit then one would need to explain how they came into being, and it would eventually recurse into Unit. From nucleosynthesis to procreation, it’s Unit all over. The way I grasp it, mathematics is a coloring of Unit, just like for seeing wind one need to sprinkle something over it. It boils down to the ascription of Parts within Wholes. Parts are mere subjections.

[1] https://www.reddit.com/r/holofractal/comments/6wnekw/this_be...

Re: Intuitionism

#148

Because humans never experience anything in and of itself, but only the output of the interaction between sensory data and a brain, literally everything is purely the result of human mental activity.

Presumably the mental activity is itself explained by independent external reality. Intuitionists say there is no such independent reality for mathematics.

Re: Intuitionism

#149

Earlier quoted context omitted.

> math describes (fragments) of reality; This is only possible if math itself is real. Note that I am not saying that a particular axiom system like Euclidean geometry has some sort of "real physical manifestation". No, what I am saying is that logical reasoning itself is real. And our reasoning about logical reasoning is certainly real as well, even if logical reasoning itself happens in very abstract form. Math its…

I like to draw a distinction between real and ideal. I insist that math is ideal. it models reality ideally. this distinction is important because otherwise we mix together something, and the ideas and concepts (e.g. symbols and rules) we use to describe and model said something. the game is not real. people playing the game are real, the game getting played is real. the game on its own as may be described in symbols…

You can say that a certain axiom system models a certain part of reality in an ideal way. But whatever is ideal, is also real, because otherwise there is nothing that could model anything. So your intersection of reality and ideality is just ideality itself.

Re: Intuitionism

#150
post #129
post #66

Earlier quoted context omitted.

I agree with you here, at least in the sense that the system is definitely not physical. You didn't answer my question, though. Is it real?

All information that exists is physical, encoded in a physical substrate. Beads in an abacus, holes in a punched card, distributions of charge in a computer memory. Hypothetical information that is not encoded physically cannot be causal. A book or computer program that have not been written can have no effects. Only information that exists in a physical encoding can be causal, by virtue of it’s physicality.

Not sure where you are going with this. What is causality? Is there a non-mathematical way of making it precise? And if I have found some way to make it precise, does it matter if I write it down here in this HN comment, or on a piece of paper, or just think it? Is the mathematical content different depending on how it is expressed in physical reality?
Post reply on HN