With the creation of the huge empire of Alexander the Great, many things changed in the political, social, psychological and philosophical life of the ancient Greeks. The small city-states of Greece ceased to exist. In those cities, citizens were accustomed to holding certain important roles for the political life of their place. Suddenly becoming citizens of a vast empire, their concerns and moods changed. At this critical juncture, the new philosophy came to play an important role in the spiritual support of individuals.
The Stoic philosophy, which was developed during the Hellenistic times and evolved until the end of the Roman times is divided into ancient, middle and new Stoa. The founder of the ancient Stoa was Zeno (333-262 BC), who was known for his simplicity and ethos. In contrast to the dualism between Platonic and Aristotelian philosophy, Zeno turned to the archaic philosophy of Heraclitus. He believed that every real being, even the soul or God, is considered bodily. He also believed that matter is in constant change but the fixed base of the spirit ensures the unity of the world. In his opinion, this unity makes all beings related and this is the sympathy of everything that leads to world harmony. He also advocated that the universe was created on the basis of a certain design by a creative mind and that everything that happens in it has a purpose.
Passions, such as desire, pleasure, fear and sorrow, were attributed by Zeno to a wrong judgment. Also, according to the philosopher, scientific knowledge is necessary in order for the moral act to take place. Zeno divided people into sages and fools, considering as sages those free from passions and like God.
The most systematic of the philosophers of the ancient Stoa, however, was Chrysippus (280-210 BC). He taught that the universe ignites from time to time to become again from the beginning and in fact the same as before. He also considered the soul to be a fiery substance that is born in the blood and dies with the body. He believed that the senses, sexual ability, language and logic are parts of the soul. Finally, he stressed that the human will is free and allows the ego, after thought, to take responsibility for its actions.
An important representative of the middle Stoa was Panaitios (185 - 109 BC). He justified human passions and recognized logic as the regulator of spiritual balance. He also emphasized that the will of man cannot be changed even by God.
Panaitos considered that the superiority of man is due to his logic and distinguished in him four spiritual impulses: for knowledge, for social coexistence, for the conquest of goods and for peace of soul. According to the philosopher, wisdom, justice, bravery and self-control develop from these impulses.
Poseidonios (135-51 BC) also belonged to the Middle Stoa. In his conceptions coexisted Greek and Eastern wisdom, mysticism with rationalism, belief in both miracles and causation, theoretical and empirical thinking, personal observation and historical tradition. As a carrier of life in the organic world he considered heat, a fiery breath that is identified with speech. He also believed that the world was a huge living organism with a soul of reason. Poseidonios considered the human soul to be fiery and argued that harmony and beauty arise from the opposites of the world.
Poseidonios believed that logic distinguished man from animals and that this was the driving force behind the evolution of civilization and not necessity. From a moral point of view, the philosopher advocated that man ought in thought and action to follow his logic because only in this way can he live a life in accordance with his nature. Finally, he believed that for human happiness, in addition to virtue, there must also be health, strength and other goods.
The representatives of the new Stoa belong to the first two Christian centuries. Their views approach Platonism, advocate man's relationship with God, and emphasize love for fellow human beings. A well known representative of the new Stoa was the slave Epictetus (50-135 AD). He believed that within man there is a space that is inaccessible to material power and to the temptation of external goods. He also believed that being indifferent to things which he can not control, someone can get rid of passions. An admirer of the Epictetus was Marcus Aurelius (121-180 AD), who wrote that knowing that everything changes, one can not desire anything and be afraid of anything outside, submitting to the natural course of the world and thus cultivating his inner freedom, which is in accordance with his rational nature.
