Ionia’s greatest and most important contribution was that provided by the audacity of the great thinkers and observers of the sixth century, that indeed which, by setting the whole conception of the world on a new basis, was bound to destroy the fair illusion of gods in the form of men which Æschylus and Phidias might still have regarded as a truth. It was only on Ionian soil, on the soil of Homer, that man had courage and strength to fling aside all convention, all tradition, to step into the centre of the universe himself and say “Thou art naught but what I recognise as thee, thou signifiest what I discover in thee.” The idea was not at the outset formulated with this precision, but such is the spirit in which the Ionians early went to work—not the philosophers alone, but the reckless natures who in the world of action took themselves for the standard of conduct—men like Archilochus the poet, whose subjectivism combined with his brutal outspokenness and license aroused the delight and horror of his contemporaries and of posterity. A terrible moral danger lurked in this attitude, and Ionia, which changed nothing but its masters, brought an infection into the mother-country which neither the state nor society availed to overcome. But for strong natures it also provided the remedy, and the world, for its part, owes to this Ionic element the best of what the Greeks have bequeathed to her—science, philosophy, natural science, and history, though it is true that they had first to be ennobled by the Athenians. This is most easily seen in the case of history.
Natural science had begun, at a stroke, to explain genesis (das Werden) in general and particular by a bold hypothesis. The investigator made the laws. Natural science, in its turn, came to test its laws by a thousand patient, minute, independent observations of nature, to accumulate the facts from which the rule might be deduced in its turn. Most important for this purpose is the cultivation of that domain in which pure abstraction permits of an unbroken series of proofs, the domain of numbers and geometrical concepts. Here we have a genuine process of learning from which, in time, mathematics takes its name; here the deceptive character of sensuous perceptions is as clear as the existence of knowable laws; here are revealed the necessity and possibility of many to collaborate and continue the work. It was not by means of his religious brotherhood, which, if it had lasted, would have ultimately become a sect, that Pythagoras exercised a beneficent influence, but by the methodical organisation of study, which became scientific in so far as it turned its attention to mathematics. At the same time, in spite of all premature hypotheses, medicine, the branch of observation most closely in touch with actual life, discovered by keen observation and continuous experiment the right way to gain a knowledge of the human body, its nature, its sufferings, how to keep it healthy, or if necessary how to cure it. In astronomy and medicine we have the difference between the East and Hellas most clearly manifest. Thousands of years before, the Babylonians had already observed the heavens; thousands of years before, the Egyptians had compounded prescriptions from all kinds of drugs and simples. But this was sorcery, and even the Greeks had to pay for allowing themselves to be imposed upon by it.