Aquinas and Metaphysics

The observational scientist doesn't have to prove that there are natural forms, he can just presuppose that. In this sense the observational sciences learn more about the material structure of reality but do not as such treat or resolve more basic philosophical questions which remain irreducible. This means you can be a scientist without being overtly a philosopher of nature so long as you presuppose a certain amount of realism regarding our contact with nature through the senses philosophically understood through direct experience.