What is Natural Philosophy?
The short answer is ‘the precursor to modern science’, however this does not convey the full flavor of the scholarly pursuit. Who better than the 13th century Practitioner Robert Bacon to flesh out the definition:
Natural Philosophy is concerned with a principle of motion and rest, as in the parts of the elements fire, air, earth, and water, and in all inanimate things made from them, as metals, stones, salts, sulphur, and colors such as red lead and white lead and lapis lazuli, which is bright blue and green, and such things as are generated in the bowels of the Earth. And similarly plants, such as herbs, trees, cabbages, reeds, and bushes; and there are brute animals and man. In all these there is naturally a principle of motion and rest and thus there is in them a nature which is called a principle of both motion and rest and are moved naturally, as is obvious with respect to local motion, and other motions, and with respect to generation and corruption, alteration, augmentation, and diminution. Similarly the celestial bodies have a principle of motion within themselves, but not a principle of rest as do terrestrial bodies.
(Paraphrased from Edward Grant's translation of Bacon's Liber primus communium naturalium in A History of Natural Philosophy)Join the College!