Chrysippus - Physics

Physics

Chrysippus insisted on the organic unity of the universe and the correlation and mutual interdependence of all its parts. He said, "the universe is its own soul and its own controlling mind." Following Zeno, Chrysippus determined fiery breath or aether to be the primitive substance of the universe. Objects are made up of inert formless matter and an informing soul, pneuma, which provides form to the undifferentiated matter. The pneuma pervades all of substance and maintains the universe as a unity and it constitutes the souls of human beings. The elements change into one another by a process of condensation and rarefaction. Fire first becomes solidified into air, then air into water and lastly water into earth. The process of dissolution takes place in the reverse order, earth being rarefied into water, water into air and air into fire. Each human soul is part of the universal soul. The human soul was divided by Chrysippus into eight faculties: the five senses, the power of reproduction, the power of speech and the "ruling part" which is located in the chest rather than the head. Individual souls are perishable, but, according to the view originated by Chrysippus, the souls of wise people survive longer after their death. No individual soul can, however, survive beyond the periodic conflagration when the universe is renewed.