Philosophy Now Forum

According to the law of non-contradiction, if a proposition is true it is not also false

What I want to ask is whether that principle of Reason has to be understood to be a necessary truth, or can it be understood to be a contingent truth?

That is, what I'm asking is whether understanding it to be contingent will generate contradictions.

I don't think it will - I think it can be understood to be a contingent truth and that any attempt to show doing so will generate contradictions will beg the question. But interested to hear the thoughts of others.

You aren't alone, Dialetheism asserts that there are true contradictions. It just comes at a cost.
Here's a good Youtuber (Kane B) discussing the notion.
There are true contradictions

In logic, the law of non-contradiction (LNC) states that contradictory propositions cannot both be true in the same sense at the same time.
https://en.wikipedia.org/wiki/Law_of_noncontradiction

My usual is, the first thing to establish is what is the human-based framework and system of realization and knowledge [FSRK], the propositions are conditioned upon.

In the above, the LNC is valid specifically within the human-based logic FSRK and no other.
Even within the logic FSRK, what is critical is it cannot be in the same sense, again is in reference to some sort of FSRK or other conditions.

There can be supposedly 'true contradictions' within paraconsistent logic or Dialetheism, they are only valid with qualification to some specific sense, within the same sense & relevant conditions.

In generally we can state within dialetheism a person bald and not-bald at the same time, but the sense has to be in a very specific sense or condition of how we arrive at say 50% and 50 half bald.
Do we count the number of hair of what it takes to be 100% not bald?
Do we measure the space without hair?
What about the fine hairs, length of hair etc?

We can agreed upon the criteria, thus the specific sense.

Moonraker wrote: ↑Thu Jan 25, 2024 5:36 am According to the law of non-contradiction, if a proposition is true it is not also false

What I want to ask is whether that principle of Reason has to be understood to be a necessary truth, or can it be understood to be a contingent truth?

That is, what I'm asking is whether understanding it to be contingent will generate contradictions.

I don't think it will - I think it can be understood to be a contingent truth and that any attempt to show doing so will generate contradictions will beg the question. But interested to hear the thoughts of others.

I don't know what necessary and contingent mean here. When we agree to think in the three basic laws of thought then contradictions aren't possible.

Moonraker wrote: ↑Thu Jan 25, 2024 5:36 am According to the law of non-contradiction, if a proposition is true it is not also false.

The way to wax lyrical/philosophical bout this is to simply reify the propositional attitude itself.

Ok... and what is a proposition exactly? Does a proposition itself have any sort of qualities; or properties of interest? Of course!

Could a proposition be true in one instant in time and false in the next?
Could a proposition be true in one location in space and false in another?
Could a proposition that is true become false; or a proposition that is false become true?

If I utter the proposition "It's dark outside." at 3am but you only read it at 11am is the proposition true or false?

Given that the proposition was true at 3am and was also false at 11am at what moment in time does the change from truth to falsehood occur exactly?

How much time did the proposition's transition from true -> false take?

Once you reify "change" and "time" in such a manner then a contradiction is nothing more than the exact point in space or time, the line-in-the-sand where truth becomes falsehood; or falsehood becomes truth.

Skepdick wrote: ↑Fri Feb 02, 2024 7:31 am
If I utter the proposition "It's dark outside." at 3am but you only read it at 11am is the proposition true or false?

If you utter the proposition, "I am a policeman", I know what the answer is.

Skepdick wrote: ↑Fri Feb 02, 2024 7:31 am Given that the proposition was true at 3am and was also false at 11am at what moment in time does the change from truth to falsehood occur exactly?

How much time did the proposition's transition from true -> false take?

Once you reify "change" and "time" in such a manner then a contradiction is nothing more than the exact point in space or time, the line-in-the-sand where truth becomes falsehood; or falsehood becomes truth.

If you're making a 3-dimensional statement about the 4-dimensional natural world, then you haven't broken the LNC, you're merely being a Skepdick.

Atla wrote: ↑Fri Feb 02, 2024 9:43 am

Skepdick wrote: ↑Fri Feb 02, 2024 7:31 am Given that the proposition was true at 3am and was also false at 11am at what moment in time does the change from truth to falsehood occur exactly?

How much time did the proposition's transition from true -> false take?

Once you reify "change" and "time" in such a manner then a contradiction is nothing more than the exact point in space or time, the line-in-the-sand where truth becomes falsehood; or falsehood becomes truth.

If you're making a 3-dimensional statement about the 4-dimensional natural world, then you haven't broken the LNC, you're merely being a Skepdick.

Dumb sophist. What's the dimensionality of change?

Skepdick wrote: ↑Fri Feb 02, 2024 9:48 am

Atla wrote: ↑Fri Feb 02, 2024 9:43 am

Skepdick wrote: ↑Fri Feb 02, 2024 7:31 am Given that the proposition was true at 3am and was also false at 11am at what moment in time does the change from truth to falsehood occur exactly?

How much time did the proposition's transition from true -> false take?

Once you reify "change" and "time" in such a manner then a contradiction is nothing more than the exact point in space or time, the line-in-the-sand where truth becomes falsehood; or falsehood becomes truth.

If you're making a 3-dimensional statement about the 4-dimensional natural world, then you haven't broken the LNC, you're merely being a Skepdick.

Dumb sophist. What's the dimensionality of change?

Change is associated with the 4th dimension.

Atla wrote: ↑Fri Feb 02, 2024 9:49 am

Skepdick wrote: ↑Fri Feb 02, 2024 9:48 am

Atla wrote: ↑Fri Feb 02, 2024 9:43 am
If you're making a 3-dimensional statement about the 4-dimensional natural world, then you haven't broken the LNC, you're merely being a Skepdick.

Dumb sophist. What's the dimensionality of change?

Change is associated with the 4th dimension.

I didn't ask you about change in 4 dimensions.

I asked you about change in general. Even within infinite dimensionality.

Skepdick wrote: ↑Fri Feb 02, 2024 9:50 am

Atla wrote: ↑Fri Feb 02, 2024 9:49 am

Skepdick wrote: ↑Fri Feb 02, 2024 9:48 am
Dumb sophist. What's the dimensionality of change?

Change is associated with the 4th dimension.

I didn't ask you about change in 4 dimensions.

I asked you about change in general. Even within infinite dimensionality.

Again, change is associated with the 4th dimension, time.

"It is dark" is a statement about here and now in 4 dimensions, so it doesn't apply at another time.

Duh?

Atla wrote: ↑Fri Feb 02, 2024 9:54 am

Skepdick wrote: ↑Fri Feb 02, 2024 9:50 am

Atla wrote: ↑Fri Feb 02, 2024 9:49 am
Change is associated with the 4th dimension.

I didn't ask you about change in 4 dimensions.

I asked you about change in general. Even within infinite dimensionality.

Again, change is associated with the 4th dimension, time.

"It is dark" is a statement about here and now in 4 dimensions, so it doesn't apply at another time.

Duh?

Dumb sophist.

What is the duration/length of a change in the 4th dimension?

Harbal wrote: ↑Fri Feb 02, 2024 9:38 am

Skepdick wrote: ↑Fri Feb 02, 2024 7:31 am
If I utter the proposition "It's dark outside." at 3am but you only read it at 11am is the proposition true or false?

If you utter the proposition, "I am a policeman", I know what the answer is.

Obviously. Because I told you the answer.

Skepdick wrote: ↑Fri Feb 02, 2024 9:55 am

Atla wrote: ↑Fri Feb 02, 2024 9:54 am

Skepdick wrote: ↑Fri Feb 02, 2024 9:50 am
I didn't ask you about change in 4 dimensions.

I asked you about change in general. Even within infinite dimensionality.

Again, change is associated with the 4th dimension, time.

"It is dark" is a statement about here and now in 4 dimensions, so it doesn't apply at another time.

Duh?

Dumb sophist.

What is the duration/length of a change in the 4th dimension?

One possibility is planck-time, another possibility is that time can be divided infinitely, and so on.

Anyway we can't match that speed so our statements are just approximations.

Duh?

Atla wrote: ↑Fri Feb 02, 2024 10:00 am One possibility is planck-time, another possibility is that time can be divided infinitely, and so on.

Anyway we can't match that speed so our statements are just approximations.

Duh?

Dumb sophist.

You can divide a line infinitely. That doesn't in any way address the question of how long the line is.

All units-definitions are circular. including the planck-length definition.

The speed of light is defined in terms of time.