Karl Popper - The World of Parmenides: Essays on the Presocratic Enlightenment

Essays on the Presocratic Enlightenment

Karl R. Popper

Edited by Arne F. Petersen , with the assistance of Jrgen Mejer

The present book contains various attempts to understand early Greek philosophy, on which I have worked for many years. I hope that these essays may illustrate the thesis that all history is, or should be, the history of problem situations, and that in following this principle we may further our understanding of the Presocratics and other thinkers of the past. The essays also try to show the greatness of the early Greek philosophers, who gave Europe its philosophy, its science, and its humanism.

The essays have not been arranged in the order in which they were written. After one of the oldest essays, 'Back to the Presocratics', which presents some early attempts at understanding the main interests and achievements of the Presocratics, there follow a number of essays on the central problems that Xenophanes and Parmenides may have worked on. These later essays have been rewritten many times during recent years, and only one of them ( ) has been published before. They supersede in some respects 'Back to the Presocratics', though that essay does deal with problems partly different from the more recent ones. This should also explain why there are recurrent themes and repeated attempts at rendering the ancient Greek texts: different translations have been retained in this collection since the main themes appear in different contexts and light from essay to essay light reflected from the splendour of Presocratic philosophy.

The longest of the unpublished essays ( ), originally entitled 'Rationality and the search for invariants', dates back to the 1960s. It tries to show that Heraclitus ('everything changes') and Parmenides ('nothing changes') have been reconciled and combined in modern science, which looks for Parmenidean invariance within Heraclitean flux. (As Emile Meyerson pointed out, this is done in physics by differential equations.) The final title of this essay indicates that 'the search for invariants' may advantageously be replaced by a theory of understanding founded on Xenophanes' early ideas.

When as a 16-year-old student I first read Parmenides' wonderful poem, I learnt to look at Selene (the Moon) and Helios (the Sun) with new eyes with eyes enlightened by his poetry. Parmenides opened my eyes to the poetic beauty of the Earth and the starry heavens, and he taught me to look at them with a new searching look: searching to determine, as does Selene herself, the position of Helios below the Earth's horizon, by following the direction of her 'eager look'. None of my friends whom I told about my rediscovery of Parmenides' discovery had looked for this before, and I hoped that some of them liked it as much as I did. It was, however, only some seventy years later that I realized the full significance of Parmenides' discovery, and this made me realize what it must have meant for him, the original discoverer. I have tried since to understand and explain the importance of this discovery for the world of Parmenides, for his Two Ways, and its great role in the history of science, and especially of epistemology and of theoretical physics.

As mentioned, these essays overlap in a number of respects, showing repeated attempts to solve the problem of understanding the ideas of the Presocratics. I apologize to my readers if the repetition is sometimes excessive. I am grateful, though, to my friends, in particular Arne F. Petersen, for their determination in putting together and editing the essays, in spite of their knowing that I am not an expert in this field, that I am a mere amateur, a lover of the Presocratics. I think that the essays reveal that I love three cosmologists above all the others: Xenophanes, Heraclitus, and Parmenides.

Karl R. Popper
Kenley, 27 February 1993