One natural world, known by measuring it. Test hypotheses and report findings that others can replicate.
Fills both slots
Naturalism + Positivist Epistemology
Key thinkers: Auguste Comte, Karl Popper, Carl Hempel
The longer story
The scientific tradition seeks generalisable knowledge through systematic observation, measurement, and hypothesis testing. It's unfashionable in some arts contexts, but if you want to know whether something actually works—not just how it feels—this is the toolkit.