To study the mechanism used to maintain constants, we must define exactly what constancy means. According to Cannon's principle of homeostasis, constants have been considered to correspond to a dynamic balance that results from the continuous operation of two opposing factors. And it was conceived that by acting concomitantly as coupled antagonists, these factors or groups of factors insure constants. The intervention of these two opposite factors becomes apparent only if an exterior cause upsets their balance.

However, our study of the processes through which dynamic balance is maintained has permitted us to recognize a different mechanism than the one which is commonly accepted.

A value considered to be a constant for an entity is not fixed or static. It represents, rather, a statistical value, the result of a series of dynamic changes which must also be considered in terms of time. Consequently, a constant has to be seen not only as the average value of a series of organized changes, but also must be identified by the characteristics of the variations. An average value around which variations occur thus represents the first attribute of a constant. The second attribute is the existence of a rhythm in the variations, the third involves intensity of variations. For instance, when we say that human body temperature is constant, we mean that 37°C is average value for oral temperature, and also that body temperature presents characteristic variations having a 24-hour rhythm and also that the occurring changes consist of variations of a few tenths of a degree above and below the average value.

The two antagonistic intervening factors do not operate concomitantly to maintain a constant value, but rather act alternately, each being predominant for a period of time. The result is not a continuously steady value for the constant, but an oscillatory movement with successive passages from one side to the other of the average value. This oscillatory movement appears to be the general rule throughout nature, prevailing in everything from the waves in the smallest subatomic particles to the pulsation of the universe. The rhythm periods appear to correspond to environmental rhythms. A rhythm related to the day, for instance, is seen for temperature. In other constants we recognize a 12-hour rhythm which could correspond to that of the ocean tides. Other rhythms, with periods ranging from two hours to a few minutes are seen for several changes occurring in blood. There are also some in which the influence of the moon is evident; for example, the hypophysis ovarian cycles; and for others, the influence of the seasons is apparent.

Teleologically speaking, balance represents a very effective method for maintaining constants. Any deviation in any direction as a result of an external intervention will be counteracted by the opposing phase of the oscillatory balance. This occurs because of the existence of two phases of the oscillatory movement itself. Such would not be the case if there were fixed values for constants.

Related to the pattern of the organization of matter in general, this oscillatory movement can be considered to be another instance in which the two opposite fundamental forces of heterotropy and homotropy, which are basic to progressive hierarchic development itself, also operate. This oscillatory balance can be related ultimately to the alternate successive intervention of the heterotropic and homotropic trends in the organization and the manifestations of entities existing in nature.