A Greek named Empedocles (who was not from Miletus, but rather Sicily) was the first to propose the four basic “elements.” These four elements were earth, air, water, and fire. These elements had a much different definition from that which chemists use today (which we’ll get to later). Unlike the modern definition of an element, Empedocles’ understanding of an element did not require it to be a pure substance. Water, for example, was obviously not the only liquid Empedocles had ever encountered. Earth represented solids, water represented liquids, air represented gases, and fire represented heat.