A(n) is a way of thinking or a set of ideas about particular subjects.
a. philosophy
b. theorem
c. proof
d. axiom

I believe the answer is: A. philosophy

Philosophers would focus on studying general and fundamental problems in life, usually revolve around existence, knowledge, mind, value, reasons and language. Even though the subjects may vary, several well-known philosophers contributed to the development of applicable science.

answer; the natural law school;