Isaac Newton, in his Mathematical Principles of Natural Philosophy of 1687, used the heading “Axioms (or laws)” for what we know as the three laws of motion. The term “axiom” puzzles me, because an axiom should be a given, requiring no further proof, and used as a premise when reaching a conclusion. But in this case the axiom (or law) seems to be something that Isaac Newton is setting out to prove applies universally, to celestial bodies as well as objects on Earth.