Finding out what the fundamental nature of a thing is, and then pursuing that thing in line with that nature.
What is the fundamental nature of G-d? Well, He has no power greater than Him yet is not chaotic and whimsical. So He can do whatever He wants but will not do just anything. Therefore, He has a nature. He has a conscience.
What is the fundamental nature of religion? Well, it's about finding spiritual truths that apply to the human condition, psychological and emotional, moral and ethical, who and what we are.
What is the fundamental nature of science? Well, it's about finding facts that can be tested as simply as using water to find level and cut stone to that level, or as complicated as measuring the "ticking" of a cesium atom.
Notice I DID NOT say it was about finding truths. So everyone trying to deconstruct Judaism by reading Paul Davies... understand the difference, because the theologians of modern science who think it about great heady epiphanies and truths sure won't.