This theory used the four elements, namely fire, water, earth and air, of which, fire and water were considered as total opposites, and earth and air, also considered as total opposites, to explain the idea of matter. Matter was considered to be combinations of two or more of the four elements, thus the Greeks attempted to explain that different substances were made up of different combinations of elements. Using the theory of the four elements, the Greeks also explained that different kinds and types of the same element were mixed with different degrees and proportions of the same element combinations. The Greeks also explained that using the theory, the elements could be changed into one another by the addition or removal of different elements, and those elements had a tendency to separate in space, with the four elements having different areas, such as fire moves outwards, and earth has a tendency to move inwards towards Earth. This theory attempted to explain the relationships between the qualitative properties of substances.

Flaws in the Theory

However, some of the flaws in this theory was that it could not explain certain scientific occurrences, like the fact that it could not explain the quantitative results one can obtain from many scientific experiments and set-ups. Also, through the Greek concept, it was held that these elements were held to exist in an ideal pure form, however in truth, it held one flaw, that these elements could not actually be found on Earth. Another flaw in the theory that these four elements could not be further subdivided, in actual fact; the smallest particle we know today is a sub-atomic particle, e.g a neutron. Also, it was a flaw to base all matter on Earth as a combination of only four of the elements as stated in the Greek theory.

The Theory of the Elements and Modern Science

In the past, man believed that matter comprised of only four elements, fire, water air and earth, as stated in the Greek theory. Today however, we know this to be false, and that the new idea of matter we know today is that matter comprises of atoms, and in accordance with the kinetic particle theory, changes in the matter itself, such as liquid and gas actually is due to the changes in state of the matter itself. This is vastly different from the previous theory held, that matter comprised of only for elements, and today we know that matter is comprised of far more elements, all originating from atoms. Today, we also know that changes of state do not occur with the combinations of the four elements, instead, changes of state come about with increase or decrease in temperature and pressure acting on the object. And also, based on the kinetic particle theory, matter does not come by with combinations of the four base elements; instead, the particles in the matter itself have the energy of movement, the higher the energy, the faster the movement of particles, and the faster the particles break away from one another to change state, and vice-versa when the lower the energy, the slower the particles move, and thus particles vibrate more slowly, and form bonds with each other to form a solid or a change in state.