On the other hand, the ideas/concepts represented under the name "empty set" certainly do exist. They're functional and purposeful. So also is my imaginary hippopotamus friend: he exists too, but also not at the store. — tim wood
The problem is, as I demonstrated, the concept of "empty set" is self-contradicting. Sure, a contradictory concept is functional and purposeful, but that purpose is nothing other than deception.
What do you say of a chair? "Chair" is certainly an abstract noun. Actually, all nouns expect for proper names are abstract. Where do you go with that? — tim wood
I told you already, abstractions do not exist as objects. That is the oversimplification of platonic realism which Plato himself demonstrated as false. Abstraction is an activity of individual human minds, and the proposition that there is "an abstraction" which is created by numerous human minds, is dependent on both a category mistake and a composition fallacy.
First, abstraction is a process of the human mind, there is no evidence that it produces an object, called "an abstraction". There is recollection of the image, representation with symbols, and application, but no evidence of an abstracted object. The proposition, that abstraction does produce an object, "an abstraction" is a falsity intended to simplify reasoning. It is a convenient falsity, accepted because it produces efficiency, but false because it is based in the category error that mental activity, "abstraction", can be represented as an object, an abstraction.
And, even if we are fooled by the category mistake, and accept that mental activity produces an object, "an abstraction", we have to get past the composition fallacy involved with the proposition that there is "an abstraction" common to numerous human minds.
So, the idea of "an abstraction" is supported by a double falsity. Some human beings might argue that two wrongs make a right, because a double negation is a positive, but that assumption as well, is based in faulty principles.
I would say that the laws of Mathematics and Logic are normative principles pertaining to conduct regulation so as to make the world easier to describe and manipulate.
These normative principles cannot be given a logical justification on pain of circularity, rather their justification stands or falls with their general overall usefulness. — sime
At least someone here has a reasonable perspective. Still, there is a problem basing justification in "overall usefulness", because deception is a valid intention. So unless we allow that "useful for the purpose of deception" is valid justification, we need further principles to judge "overall usefulness". I think it is necessary to exclude "useful for the purpose of deception" as a valid justification.
Think of mathematicians sitting around a table and creating a game, discussing the pieces that are played, the environment in which they are played, and the rules that are agreed upon. Once done, would you then say, "The game does not exist."? You fail to recognize that math is a social endeavor, frequently deriving from observations of the physical world, but just as frequently not. — jgill
Saying "the game exists" has the same problem as saying "the rules exist", or saying "the concepts exist". It is an over-simplification made to facilitate communication. Each of these terms, "game", "rules", "concepts", refers to a complexity of physical objects, symbols, and mental interpretations of the symbols. To make communication smooth and swift we refer to those complexities with simple words. The problem is, that common language use which is an habitual activity, clouds our minds as to what is really behind those terms. Because we use the language as if there is an existent thing referred to by "game", "rule", or "concept", we fall under the illusion that there is such existent things.
But a careful, clear, and rigorous analysis of what is actually referred to by these words reveals that there is no such existent things. Each of these words is used to refer to a massive complexity of social interactions which we do not properly understand how to represent. So, we have a word, we assume that the word represents an existent object, and we go about our business ignoring the fact that the word does not represent an existent object, it really represents a massive complexity of social interactions which is not understood. In philosophy though, we seek to unravel these mysteries of the misunderstood, and that is why I insist on recognizing the reality that there is no existent objects referred to by these names.
From this perspective, would you say the rules are the axioms? I would say no, there are ill-defined patterns of thought that precede the establishment of the rules, and that might be the subject of study and formalization at a later time - as is the case of the foundations of mathematics. — jgill
If I understand you correctly, you are suggesting that the axioms are like proposals for rules. Each axiom is presented by a mathematician as a proposition to be accepted, or rejected, by the others. The various mathematicians will then take these proposals and try them out, relate them to each other, combine them with each other, etc., in a sort of trial and error fashion, and after some time of doing this some axioms will emerge as "the rules". I accept this representation, it's similar to the way we do science, hypotheses are presented, they are related to each other, tried and tested with experimentation, until certain theories emerge as "the rules".
Here's something we ought to respect though. The proposals don't ever change their inherent nature as "proposals", despite the fact that they get accepted into the fold as "rules". Therefore we ought not change our attitude toward any proposal just because it has obtained the status of "rule". In reality, things change, human beings and their social structures evolve, so the "rules" change accordingly. Therefore we cannot allow that a proposal, long ago accepted into the status of "rule", is beyond reproach.
Physicists thought one day there must be atoms. Then they discovered the atoms are made of protons and electrons and neutrons. Then they discovered the protons are made of quarks. Now they think the quarks are made of strings. Do any of these abstractions exist? Yes they do, in the sense that they are part of an abstract mathematical theory that explains the experiments we're capable of doing at any moment in history. — fishfry
The problem here is that you assume "they are part of an abstract mathematical theory", when there is no such unified "theory". There is a multiplicity of theories, related or connected to each other in various different ways, dependent on an individual's interpretation. So this assumption is misleading. It is the belief that the abstractions are all part of one overriding theory, which gives credence to the claim that they exist. Once we recognize the falsity of this assumption, the assigned unity is lost, and the entire structure which depends on the reality of this unity, falls apart into individual ideas in individual human minds. The assumed reality of these ideas, as existing "abstractions" is dependent on this unity of "an abstract mathematical theory", which is not supported or justified.
Physicist invent new existing things all the time. And de-exist things to. The luminiferous aether was once regarded as existing, till Michelson and Morley couldn't find it and Einstein did away with its necessity. — fishfry
Again, to call these things "existing" is an over-simplification designed to facilitate communication. That we say at one time X exists, and later x does not exist is an indication of this. At one time we are comfortable using these theories, that is the convention, so we talk as if they exist, at another time we are not comfortable using them, they have become unconventional, so we talk as if they do not exist. Using the word "exist" is just a convenient fiction to refer to what is and isn't conventional. But if we take that fiction literally, and assume that because a conventional idea "exists", it is therefore an object, and we try to treat the idea as an object, we have been misled down the path of misunderstanding.
A scientific entity has existence when it's a necessary ingredient of a successful physical theory. — fishfry
Again, you are over-simplifying, referring to a "physical theory" as a unified object. Every theory is interpreted in numerous different ways, by numerous different people, and one interpretation may be demonstrated as unacceptable while another one is acceptable, so there emerges a conventional interpretation.
I gather you call "real" only what is "really out there." But if the 20th century taught us anything, it's that the existence of such a thing as "real things out there" is an assumption and not a fact. I believe if I'm not mistaken this is called scientific realism. It's only an idea. We could kick it around. But you have no logical basis for claiming it's true and everybody else is wrong. The days of Euclidean geometry and Newtonian physics are gone. Now we know the world consists of probability waves that are everywhere at once till we measure them. What can that mean? We don't know. But you claiming that you personally know what things are real, is a delusion on your part. Since you called me delusional the other day, which I can live without. — fishfry
Sorry, there was no ill intent with the word delusional, and it wasn't meant to single you out. I think we are all delusional, it's a function of where our institutions and conventions have misled us. You might think that science has guided us to the ontology of model-dependent realism, meaning that there are no "real things out there", but this necessitates also that there are no "real things in there". So this form of "realism" is not a realism at all because it cannot validate anything as real. That's why we're deluded, we base reality on usefulness and eloquence, having dismissed truth as unreal. But without truth, eloquence is useful for, and justified through, deception.