Aristotle's First Principle

Philosopher aristotle said that there must be a first principle from which all change brings the world into being. The early group of philosophers, so called monists, came up with various suggestions. For thades, it was water. For anaximones, it was air and er for heraclitus, it became the logos. And then at the end of this series, you get empedocles, who says, well, actually, let's think of all four physical elements, earth, fire, air and water, as being the roots of everything.