PROF. BENJA U HARRINGTON'S Friday evening disclxiirsg at the Royal Institution, entitled of Early Greek Science, was delivered if February 23, 1945, and has recently beery uyished. It deserves to be widely known; for it corrects some popular misconception, and relates the scientific achievements of early Greeks to their social background. The misconception arose from Aristotle's presentation of the ‘physical’ philosophers of Ionia as primarily metaphysicians concerned with the general nature of things, and as pioneers in his own line of philosophic thought. Probably even in his time, those early Ionians were represented mainly by summaries of conclusions, without the observations and experiments on which they were founded. But the Ionian objective was more limited, to give "an operational rather than a rational account of the nature of things. Their question was “How it works”, and the answer was supplied, not by myths or abstractions, but by practical knowledge within their own control. Thus “technology drove mythology off the field”, not indeed from all aspects of Nature, but from those which could be illustrated by the technical equipment of the age. Hence the nomenclature and imagery of science, derived from arts and crafts, which Prof. Farrington illustrates from Lucretius, the Roman interpreter of Anaxagoras; from the caricature of the method by Aristophanes in the “Clouds”, by the experimental basis of Pythagorean mathematics, and by the Hippocratic physiology, “to observe the invisible by means of the visible”.