Skip to main content

All Questions

Filter by
Sorted by
Tagged with
24 votes
8 answers
4k views

What do all branches of Mathematics have in common to be considered "Mathematics", or parts of the same field?

At some point in my life I think I've read what all branches of Mathematics had in common were numbers. But then I remembered a branch of the many Mathematics I had when I was an university student, ...
Pablo's user avatar
  • 807
3 votes
2 answers
165 views

Two kinds of abstract objects - circles and sets

Both circles and sets are considered abstract objects. I can visualise a circle in my mind (can 'see it through my mind's eye') but can't visualise a set or a number. I have no picture of a set in my ...
Harshit Rajput's user avatar
3 votes
3 answers
368 views

"Impredicative" definitions in mathematics

In this blog post, the following definition of an "impredicative definition" is offered: A definition is said to be impredicative if it defines an object E by means of a quantification over a ...
Frank's user avatar
  • 2,501
1 vote
0 answers
101 views

Is 'a level of quantity' a poor definition of 'real number'?

I was thinking about how we define numbers with respect to their uses, and came up with the definition of 'a level of quantity' which can have a different physical consequence for each quantity ...
Confused's user avatar
  • 1,237
1 vote
4 answers
289 views

Is '=' a relationship between the objects or their expressions?

The Wikipedia definiton of equality gives it as a 'relationship between two expressions' This confuses me as when we define mathematical expressions like 2+2=4 it makes no sense to say that '=' or '...
Confused's user avatar
  • 1,237
3 votes
3 answers
151 views

Can an 'abstract object' be a collection of constituent parts?

When I ask this, the use of collection or set is not necessarily 'mathematical', so if in this case I mean a collection of ideas that encapsulate it, 'make up' the idea in the same way the various ...
Confused's user avatar
  • 1,237
0 votes
1 answer
148 views

When does 'number' become 'quantity'?

Numbers themselves are simply conceptual objects, but when does number become a quantity? Is the 'cardinality' of a set a 'quantity'? it is a count but we represent it with just a number that we ...
user avatar
0 votes
1 answer
160 views

Is there an alternative to infinity?

We can say that a discrete set with 1 and 2 allows us to count just from 1 to 2 but a sequential set with 1 and 2 allows us to count from 1 to 2 in an infinite way (1.1, 1.2, 1.3 ...) but no man can ...
justathought's user avatar
1 vote
3 answers
183 views

Definition of 'Identity' [duplicate]

This may seem like a very specific or stupid question, but I'm new to this, I'm interested in the idea of 'identity' and 'identical. I've heard some description of the idea different 'copies' or ...
Confused's user avatar
  • 1,237
1 vote
3 answers
335 views

Mathematical objects existing as different instances

I have a slightly complex conceptual question about the idea of 'multiple' instances of mathematical objects. In particular Real Numbers, and generally the idea of having multiple instances of ...
Confused's user avatar
  • 1,237
0 votes
3 answers
112 views

Is there any philosophical difference between "I have no horns" and "I have horns, but they have zero volume"?

The common idea is that, on one hand we have "I don't have X", on the other hand we have "I have X, but X has some its quality equal to zero, making it to behave the same way as if it ...
KarmaPeasant's user avatar
3 votes
7 answers
614 views

Is there an idea of non-spatial reality in philosophy?

Our world is spatial. In particular there are 3 dimensions and we can measure lengths of objects in either of them. However, when thinking about metaphysics I came to the conclusion that there might ...
rus9384's user avatar
  • 2,764
4 votes
1 answer
185 views

What should be the definition of absurdity?

I several times have encountered questions, asked by myself and other people about different things, subjects, phenomena, considered to be absurd to common perception. But, sometimes through rigourous ...
Mockingbird's user avatar
6 votes
3 answers
768 views

What is the fallacy of defining a square as “a closed-plane figure whose sides are all equal”?

I am determined to prove my professor wrong. Here is a question from a recent exam: Using the six definitional criteria, evaluate the following definition. A square is a closed-plane figure whose ...
Oscar Wilde's Lover's user avatar
6 votes
4 answers
431 views

What does the term "mathematical logic" mean?

What is "mathematical logic"? Is it the logic of mathematical reasoning, or is it the claim that mathematics and logic are identical? Also, is "quantificational logic" a particular type of "...
Geremia's user avatar
  • 8,615
6 votes
2 answers
736 views

What does Russell mean by "term" in Principles of Mathematics?

Bertrand Russell in Principles of Mathematics defines a term as "Whatever may be an object of thought, or may occur in any true or false proposition or can be counted as one." Can someone elaborate on ...
Mathmank's user avatar
  • 163
6 votes
5 answers
7k views

What is the difference between a probability and a possibility?

I ask this in a fairly naive way. I understand that "probabilities" can be quantified in frequencies, degrees of belief, etc. with some defined "space" of probability.But I know little about modal ...
Nelson Alexander's user avatar
-2 votes
2 answers
1k views

How to define a number [closed]

What is the positive real number (say less than one) that is not a rational nor an irrational number? I have encountered a mathematical problem that confused me about the definition of real numbers,...
Bassam Karzeddin's user avatar
3 votes
3 answers
1k views

Truth for logicians, mathematicians, and philosophers

How does the logician define truth? What is the precise definition of truth for mathematicians? How does a philosopher define truth? What are the similarities and differences between these ...
Inquisitive's user avatar
20 votes
9 answers
4k views

Interpret Bayesian probability as frequentist probability?

It is usually said that the Bayesian probability is a subjective concept, quantifying one's degree of belief in something, while the frequentist probability is the the fraction of certain outcomes ...
D.F.J.'s user avatar
  • 303
8 votes
3 answers
544 views

What does it mean for an axiom to be logical?

I have recently been hearing the phrase logical axiom being thrown around in reference to the philosophy of mathematics and I'm having a hard time understanding what one might mean when they are using ...
Michael Harper's user avatar
5 votes
1 answer
525 views

What does "aggregative mechanical thought" mean in Frege's works?

In *The Foundations of Arithmetic: A Logico-Mathematical Enquiry Into the Concept of Number" by G. Frege pages XV and XVi we read: A typical crudity confronts me, when I find calculation ...
Root Lopht's user avatar
5 votes
3 answers
793 views

How could the concept of 'evidence' be defined, and how significant is it?

What is evidence, and how much of it means that a proposition is true? Does a partial / total lack of evidence mean that a proposition should be ignored? Is the concept evidence more important to ...
James's user avatar
  • 51
7 votes
3 answers
245 views

What's a name for the impossibility of identity?

It appears to me that no two things can ever be identical, yet the notion that they can has been deployed rather without pause about a billion times in theoretical literature in philosophy and ...
themirror's user avatar
  • 171
1 vote
1 answer
224 views

The represenation of nothing

If zero is the representation of nothing, then nothing must me something because it is being represented, correct? Now, if the above is incorrect, and zero is actually nothing, then why is it that ...
IT Ninja's user avatar
  • 113
7 votes
2 answers
272 views

Genus-Differentia and Mathematical Categories

I am a mathematician by training. Category theory has become a major subfield of mathematics --- major enough that some have tried to recast the logical foundations of mathematics in terms of ...
Barry Smith's user avatar