How does human perceive the existence of universals?

[B Milligan]

In geometry class, when we draw a general triangle, we're bound to draw a triangle that's either right, or acute, or obtuse, but cannot draw general one.In that case, in what form does the general triangle exist?

[Genady]

According to a major school of thought in psychology and philosophy, concepts exist separately from their various sensory, motor, and affective representations.

Using a triangle example, Kemmerer in Concepts in the Brain (pp. 253-254, Oxford University Press) says,

Quote

nothing in a particular image of a triangle tells us that “having three sides is what’s important for trianglehood.” ... once you state that as the critical feature, you’ve gone outside of what visual images can do.

 

[davidoliver]

The perception of universals, or the idea that there are qualities or concepts that exist independently of particular instances, has been a topic of philosophical debate for centuries. There are different theories about how humans perceive the existence of universals, but I'll provide a brief overview of two prominent positions.

[Eise]

As said in the previous reactions, the general triangle exists as a concept. As you correctly notice, you cannot draw a 'general triangle'. So, e.g. a proposition about 'the triangle' means, that it should apply to all triangles, like 'the sum of the angles of a triangle is 180^o'. 

To expand a little on 'concepts': naive ideas about language are that the words refer to things in reality. But that is not the case: words refer to concepts. If I ask you the question 'How many legs has a dog?' you have no trouble to give the correct answer. But if I ask you to visualise a dog, and then followup with 'Is it black or not?' I do not know what you will answer, because you pictured a specific dog, not 'the general dog'. The 'general dog' is not black, not brown, not white etc. But the 'general dog' has four legs.

Without concepts, language would be impossible, and with that general propositions, and with that on its turn, science. Concepts are not naturally given, so in different languages, concepts might differ too. And in science new concepts are developed again and again. Concepts are not true or false: they are useful or not. If they allow us to describe processes, ideally as a law of nature, they are useful.

Edited April 12, 2023 by Eise

[studiot]

17 hours ago, davidoliver said:

The perception of universals, or the idea that there are qualities or concepts that exist independently of particular instances, has been a topic of philosophical debate for centuries. There are different theories about how humans perceive the existence of universals, but I'll provide a brief overview of two prominent positions.

Welcome David Oliver and +1 for a good beginning answer to the op.

You may have joined at an inopportune moment during updating and spam combat which has been going on over the last few days since you obviously haven't finished your post.

I do most sincerely hope you haven't been frightened off by this disruption as SF is normally a much more convivial place for genuine folks.

 

3 hours ago, Eise said:

As said in the previous reactions, the general triangle exists as a concept. As you correctly notice, you cannot draw a 'general triangle'. So, e.g. a proposition about 'the triangle' means, that it should apply to all triangles, like 'the sum of the angles of a triangle is 180^o'. 

To expand a little on 'concepts': naive ideas about language are that the words refer to things in reality. But that is not the case: words refer to concepts. If I ask you the question 'How many legs has a dog?' you have no trouble to give the correct answer. But if I ask you to visualise a dog, and then followup with 'Is it black or not?' I do not know what you will answer, because you pictured a specific dog, not 'the general dog'. The 'general dog' is not black, not brown, not white etc. But the 'general dog' has four legs.

Without concepts, language would be impossible, and with that general propositions, and with that on its turn, science. Concepts are not naturally given, so in different languages, concepts might differ too. And in science new concepts are developed again and again. Concepts are not true or false: they are useful or not. If they allow us to describe processes, ideally as a law of nature, they are useful.

 

I also like your clear example of general v specific, +1

But I disagree with the proposition that it is impossible to specify a general triangle.

On 4/10/2023 at 4:19 AM, B Milligan said:

In geometry class, when we draw a general triangle, we're bound to draw a triangle that's either right, or acute, or obtuse, but cannot draw general one.In that case, in what form does the general triangle exist?

 

One way to do this is to turn to algebraic geometry.

A general triangle is a set of the form { (a,b), (c,d), (e,f) }  where a,b,c,d,e and f are real numbers.

Another way from another discipline would be to say

A general triangle comprises three connected words as in the 'health triangle' { social, mental, physical }

Edited April 12, 2023 by studiot

[Eise]

20 hours ago, studiot said:

But I disagree with the proposition that it is impossible to specify a general triangle.

Ah, of course you can specify a general triangle. But you cannot draw it. Take my example of 'the dog': using the definition of a 'general triangle', the question if it has a right angle cannot be answered ('the dog' being black or not). But from the definition we can be sure that the sum of the angles is 180^o ('the dog' having 4 legs).

21 hours ago, studiot said:

A general triangle comprises three connected words as in the 'health triangle' { social, mental, physical }

I consider such use of the word 'triangle' as metaphoric speech.

[studiot]

3 hours ago, Eise said:

Ah, of course you can specify a general triangle. But you cannot draw it. Take my example of 'the dog': using the definition of a 'general triangle', the question if it has a right angle cannot be answered ('the dog' being black or not). But from the definition we can be sure that the sum of the angles is 180^o ('the dog' having 4 legs).

 

I did consider the difference between draw and specify. Of course if we were Euclidian geometers, as implied in the op then we would have to construct a triangle.

But this was not the question asked in the op.

The op asked for the form of the general triangle, noting that it would not be achieved by drawing.

This was the question I addressed.

On 4/10/2023 at 4:19 AM, B Milligan said:

in what form does the general triangle exist?

3 hours ago, Eise said:

 

I consider such use of the word 'triangle' as metaphoric speech.

Not at all. Continuing the mathematical theme (this is after all a mathematical question) my use is a great example of what is mathematically termed a cyclic group of period 3.

[B Milligan]

Care to elaborate on the essence of concepts, If it's not visible, what would it be?

On 4/10/2023 at 8:36 PM, Genady said:

According to a major school of thought in psychology and philosophy, concepts exist separately from their various sensory, motor, and affective representations.

Using a triangle example, Kemmerer in Concepts in the Brain (pp. 253-254, Oxford University Press) says,

 

 

[Genady]

1 hour ago, B Milligan said:

Care to elaborate on the essence of concepts, If it's not visible, what would it be?

 

Concepts are building blocks of thoughts. 

In fMRI studies, the difference between concepts and their visual representations manifests itself, for example, in areas of brain which are engaged when a task requires thinking of something vs. when a task requires imagining that something. In the latter, the same areas are engaged as in the former PLUS primary sensory or motor areas. Presumably, engaging these primary areas is what makes the images specific.