EKPYROSIS is ‘periodic destruction’. This ancient Greek word refers to the Stoic belief in a cyclical conflagration (birth and rebirth) of the universe. So, after each destruction, the cosmos undergoes a recreation (<palingenesis>) only to suffer a destruction again at the end of the new cycle.
This kind of total catastrophe is the opposite of <kataklysmos> (inundation, the destruction of the earth by water). The idea of <ekpyrosis> is central in Stoic physics and cosmology. Stoics equate this destructive fire with the all-permeating reason (<logos spermatikos>) of the universe.
<Ekpyrosis> is ‘periodic destruction’, a notion that, according to Plutarkos (Plutarch), comes from Chrysippos ho Soleus (Chrysippus of Soli). However it is not a theory widespread among Stoics. For instance Zeno of Tarsus and Boethus of Sidon, do not agree or have different interpretations. Therefore, for some philosophers <ekpyrosis> is a positive phenomenon of “purification”. Also this cleansing of the soul is a renewal of all things belonging to the past cycle. On the contrary, for Lucan, <ekpyrosis> is a termination with no ensuing rebirth. For the Roman Poet <ekpyrosis> is the final culmination of the world.
An explanation of <ekpyrosis> is the progressive universe growth culminating with re-absorption. Another is the sun being so hot that it dries out the universe and catches fire and itself. Nonetheless, Zeno says that the great fire does not put a stop to what originates the universe. In fact the seas are the origin of cosmos and they are spared. Zeno’s preoccupation is to solve the problem deriving from the theory of elemental <anathymiasis>. Thus the fire cannot destroy the seas. A third explanation of <ekpyrosis> is the return of the planets to the original positions. When they find the places they had at the moment of creation, it starts the process of <ekpyrosis>.