Ripensare i presocratici

There is a tendency to understand the Presocratics in terms of a few simple ideas: Thales said all is water, Anaximander started with the boundless. We are in danger of missing the subtleties and complexities of their theories. We are too ready to follow the interpretations of Plato and Aristotle, failing to recognize their biases.

Early thinkers proposed “primary ideas” which suggested universal solutions to problems. Traditional explanations consisted of narrative accounts in which stories explained how things came to be, and also an intermediate area of probability. To rethink the Presocratics we must learn to reconstruct the scene as they understood it. The ideas of Presocratics are often presented out of context in a doxographic approach. We must try to reassemble them like pieces of a mosaic, using a conceptual toolbox.

Homer is the fount of Greek civilization, representing the good life among gods and mortals. The society depicted in the Homeric poems seems to be open and not overly hierarchical. The poems provided models of good behavior without being overtly didactic.

The introduction of alphabetic writing made literacy possible to the many, in contrast to earlier writing systems; it encouraged an open society and free exchange of information.

Thales was dedicated to measuring things that seemed impossible to measure: the height of pyramids, the size of the sun, the time between the solstice and the equinox. He became the first full-time researcher at a time when Greeks thought the secrets of nature were unfathomable. He dealt with particular problems, not general truths, so he was not a philosopher.

Anaximander provided the first map of the world as a disk surrounded by Ocean. His representation would allow the viewer to experience the world without traveling. He was the first to put his ideas down in a prose treatise, providing inspiration for other early thinkers.

Anaximenes first offered a single principle. His archē was air, which turns into everything, while everything turns back into air. He came to believe more firmly in natural philosophy and offered an attractive account of meteorology.

Pythagoras seems to have started out as a natural philosopher; but when he came to Croton, he apparently repudiated that approach and focused on religious activities, criticizing Homer and Hesiod.  Accounts of his advances in astronomy and mathematics remain dubious.

Xenophanes was the first thinker to clearly posit a water cycle. He recognized fossils of sea creatures on islands, suggesting these were underwater long ago. Rejecting anthropomorphic gods, he posited a single deity and prefigured negative theology. He recognized the value of scientific research and the general notion of progress.

Alcmaeon recognized that humans must infer explanations from evidence. He conducted detailed dissections and recognized the brain as the organ that governs sensation and judgment. He seems to have influenced Parmenides, Empedocles, and Hippo. In astronomy, he said the planets move opposite the sun, the sun is flat, and the moon’s phases are caused by a bowl-like structure.

Hecataeus composed a Voyage around the World as an encyclopedia of geography. In his Genealogies he tried to find historical truth in legends and myths, for the first time. He deserves the title of the fourth Milesian.

Heraclitus did not make major contributions to natural philosophy, but he raised the discussion to a new level. According to him, mortals perceive things without grasping their significance. Heraclitus’ conceptions of the logos, the unity of opposites, panta rhei, etc., are manifestations of a central insight.

Scholars often treat Parmenides exclusively as a philosopher of Being, dismissing the natural philosophy of the latter part of the poem. Despite his argument that only what-is is knowable, he went on to offer an elaborate natural philosophy. He first explained the moon’s light correctly and depicted the earth as a spherical body divided into five zones. He theorized about biological organisms and how they were generated. His deductive approach to exposition prefigured the use of logic in geometry and other fields.

Empedocles of Acragas seems to have been young when he wrote his On Nature and older when he wrote the Katharmoi. He developed a cyclical cosmology with the four elements and two cosmic powers. His biology implies he did dissections under a master: perhaps Alcmaeon? He explored botanical and zoological investigations as well as embryological studies. He was not a complete scientific thinker, but alternated between scientific accounts and fantasy.

Euthymenes of Massalia, a forgotten Presocratic, was the first navigator of the Mediterranean we can name. He seems to have sailed to the Senegal River in west Africa and to have inferred that this was another mouth of the Nile. He combined the map of Anaximander with the theory of Thales and a theory of Hecataeus to reach his conclusion.

In the mid-fifth century, Athens grew rapidly, creating a democracy and an unprecedented center of art and culture. Writings proliferated, and people began to acquire books and collect libraries. A new genre appeared in opposing arguments, written by intellectuals and appearing in dramas, speeches, and histories. The emphasis was not on wisdom but on the interplay of ideas. The new sophoi did not so much provide answers as leave their audience perplexed.

There was “virtual” philosophy among the Presocratics, especially Heraclitus. But a discipline of philosophy had not yet emerged. The basic idea of doing systematic research was the really explosive idea invented by Thales and Anaximander.

What was remarkable in Greece was the pursuit of research by private individuals. Their approach led to the scientific research of modern times. Today we are heirs of a tradition of research begun long ago in Greece.

D. G.