What’s the most effective way to debunk moral relativism / subjectivism?

[esquizofrenico]

Hi carnap:

I agree with mostly with what you are saying, but the thing is that you sound exactly like the Humanities students in my High School that complained about having to study derivatives because "they would never use them in their life". And the truth is, they were fundamentally right. I fail to see what kind of effect would have in the life of 90% of the world population believing that the derivative of the cosine of x is the logarithm function. As long as there is a widespread believe in society that mathematicians have the right answer and a lack of interest in this people in pursuing the conclusions from their idea, the life of that person would be totally unaffected. I can write d cos(x)/ dx = log(x) and the world goes on spinning.

The importance of mathematics truth is completely dependant of society context. If you don't have the technology to perform millions of calculations per second, knowing what a Fourier series is, is much less important. So when you say that the importance of breaking a moral law depends on whether that moral law is widely accepted in a society, my answer is "so what?". The truth is that due to physical reasons we are forced to live in societies, that is as much part of reality as the measuring of an scientific instrument. Saying that there are imaginable situations in which breaking a moral law would yield you no ill, is just as saying that Group Theory was pretty irrelevant to a cave man.

The only attack you can give to a farmer that says that the derivative of the cosine of x is the logarithm is "What if the guys that fabricated your phone thought as you do?". That's it. That is the same argument you can give to someone that negates a moral law. So I think if there is a difference between mathematics and morality (which I think most probably is), it is not there.

That was extremely well said, and great examples, thank you.
Can we use this (copy paste) in the Wiki?

If you're willing, maybe you can post here if you're OK with contributing generally: http://philosophicalvegan.com/viewtopic.php?f=5&t=3335

You can, but instead of Fourier Series, put Taylor Series, that is what I meant. Man, am I awful remembering people's names.

[brimstoneSalad]

You can, but instead of Fourier Series, put Taylor Series, that is what I meant. Man, am I awful remembering people's names.

Thanks!

[FredVegrox]

I believe in morality and real right and wrong being distinct, but if you are atheist it will be really difficult to get agreement from others generally, who also are, on why there would be such morality.