Recently I read an article that prompted an interesting thought. The article was about the validity of math when it comes to science. What makes math the universal language of science? Is math made up or discovered?
Whatever the answer is to these questions, the fact is that we accept math to be the universal language of science. For example, Einstein's Theory of Relativity is valid because he was able to show it mathematically. Einstein's theory of mass-energy equivelance is also valid because he has the math to show it, E=MC^2.
The interesting thing is that most of us blindly accept that if the math is there, it's valid. And why wouldn't we? There's practical value to it and it has worked for us for hundreds of years. We intellectually and practically figured out that math works and that it is the truth. So, if any science has accurate math in it, it also must be true.
Now, here's the thought: this relationship between science and math is equivalent to the relationship between the Qur'an-Sunnah and Islam. The Qur'an and Sunnah are the math of Islam. So, if there's a ruling that a scholar derives using the Qur'an and Sunnah, then it is valid. Just like if there's a theory that a physicist derives using math, it is valid.
In summary, we intellectually figure out that the Qur'an and Sunnah are the truth, then whatever is derived using the Quran and Sunnah, we must accept it. The comparison would be to Einstein coming up with the Theory of Relativity (in Islam let's say the theory is that it is forbidden to terrorize), and then him using math to prove it (in Islam it would be using Quran and Sunnah to prove that terrorism is forbidden). If the math works, then the theory works, if Quran and Sunnah work, then Islam also works.