Since it was developed, Newton's law of gravitation and many other laws of physics cannot be derived from one grand underlying principle. Deriving Newton's law of gravitation or Einstein general relativity theory, would mean that gravity emerges from something else and that would mean that the only known Newton's law of universal gravity is no longer a fundamental law of physics.
Although this might be true, I believe that everything must have an origin. I believe that there is a fundamental universal physical law from which all other known physical laws can be deduced. I also believe that the laws of physics are not picked at random but there exists an underlying principle from which they can be derived with ease. Failure for some minds to grasp this principle doesn't mean that it doesn't exist. Because I was used to deriving and proving formulae in pure math, I didn't like the way the laws of physics were presented to me without proof. A physics tutor would just write down a set of physical laws without proof. There are so many physics books which still do the same thing. Being curious and passionate to finding out how I could derive all the laws of physics from one single equation is proof that this book would have never existed in the first place if had not discovered the hidden principle that underlies all physics.
