As man attempted to recognize order in the constant changes seen in nature, he noted certain patterns that appeared to indicate definite "laws of nature." Some of these laws have been observed to operate under such a wide variety of circumstances that they have come to be accepted as "fundamental laws."

In 1824, Sadi Carnot formulated one which is known as the Second Law of Thermodynamics. Carnot observed that, in a given system, work involving the transformation of thermal into mechanical energy is only accomplished as heat drops from high to low temperature. In more general terms, this means that work accomplished in an isolated system results in progressively eliminating differences in temperature. Clausius recognized this as a fundamental principle and postulated that the amount of energy available for work always tends toward a maximum. This condition, called "maximum entropy," corresponds to uniformization of temperature and also to homogeneous disorganization. At first, it appeared that the principle was in conflict with the First Law of Thermodynamics which expresses the rule of conservation of energy. However, Helmholtz soon was able to demonstrate its validity by showing that only the second law could reconcile the first with the impossibility of perpetual motion.

In a more philosophical vein, we considered, in our research, that this Second Law of Thermodynamics in its broadest sense could define a fundamental trend toward annihilation of any existing differences in nature, through the triumph of total uniformity. Since Clausius used the term "entropy" in applying Carnot's original observation to closed mechanical systems, it has seemed preferable to avoid confusion by utilizing another term for this general tendency toward uniformity in its broadest sense. Therefore, we have chosen the term "homotropy."

Despite the theoretically rapid trend in the direction of absolute uniformity, or homotropy, no such final state has yet been achieved. It must be concluded, therefore, that some other factor opposed to that trend exists.

We have chosen the term "heterotropy" for this other factor, which tends to maintain or produce inequality and thus to preserve the order that is evident in nature.

In order to understand the roles of these two opposing fundamental tendencies in the organization of nature in as logical a fashion and with as much ease as possible, it seemed advisable to try to study their operation first in one of the simplest and best known natural organizations, the atom, passing later on to higher and lower levels of organization.