Based on the etymology of the word, physics can be defined in the following way: "Physics is the episteme of Nature, and Nature (Φύσις) is the phenomenon of spontaneous appearance and evolution." See Georgios Choudalakis' work on this at: http://www.mit.edu/~gchouda/miscellanea/physics/Physics_etymology.pdfBased on the etymology of the word, physics can be defined in the following way: "Physics is the episteme of Nature, and Nature (Φύσις) is the phenomenon of spontaneous appearance and evolution." See Georgios Choudalakis' work on this at: http://www.mit.edu/~gchouda/miscellanea/physics/Physics_etymology.pdf