Thread: About 'first principles'

I don' t understand why we called the process of finding a derivative from the definition 'finding the derivative from first principles'.
Why we have 's' after "principle"?

Originally Posted by ling_c_0202

I don' t understand why we called the process of finding a derivative from the definition 'finding the derivative from first principles'.
Why we have 's' after "principle"?

Because there is not a single principle that we start from but a number of
them.

RonL