There are many ways to define "natural forces ". The works you are about to view are painted "free from afflectation or restrain; easy,instinctively felt and not prescribed by any law".

Natural force are the four elements. Eearth, fire, water, and air are the basic four elements that all things were thougth to be created from according to the ancients or early civilizations. I like their philosophy;simple is better. This page is my rendering of those elements.