In this part of his theory, Heraclitus can be seen as expanding Anaximander's idea of the interaction of opposites and the resulting equilibrium, only with a new twist all his own. On Anaximander's worldview there was occasional strife and then a return to equilibrium through the imposition of justice on the part of the Unbounded. On Heraclitus' view, on the other hand, strife between the opposites is universal; it never ceases. In fact, it is because of strife that we have justice and equilibrium. While for Anaximander strife was beyond the plan and justice had to step in to regulate it, for Heraclitus strife is the plan.
Heraclitus's idea of strife between opposites does not have any obvious meaning for modern readers. In all likelihood it refers to the constant oscillation between the opposites. Again, the daily and seasonal cycles, in which one opposite is continually destroyed into the next, would be the prime example of this sort of strife. But strife could also be a mere tension between opposites, or the constant encroachment of one opposite upon the others. Regardless, the main thing to take away from Heraclitus's theory of equilibrium is that change and strife are the norm, not the aberrations.