In appreciating change, a useful translation of wéi and wú wéi (i.e. 為 and 無為 in traditional characters; 为 and 无为 in simplified characters) is the ways of “willful action” and “natural order” as juxtaposed. This sense goes beyond a dictionary definition of 為 and 無, into the context of science and philosophy in Chinese and western contexts, in the writings of Joseph Needham.
It seems clear, at any rate, that the early superiority of Chinese science and technology through long centuries must be placed in relation to the elaborate, rationalised and conscious mechanisms of a society having the character of ‘Asiatic bureaucracy’. It was a society which functioned fundamentally in a ‘learned’ way, the seats of power being filled by scholars, not military commanders.
Central authority relied a great deal upon the ‘automatic’ functioning of the village communities, and in general tended to reduce to the minimum its intervention in their life.
I have already written (above, pp. 1-2) of the fundamental difference between peasant-farmers on the one hand and shepherds or seamen on the other.
This difference is expressed epigrammatically in the Chinese terms wei 為 and wu wei 無為.
Wei meant application of the force of will-power, the determination that things, animals, or even other men, should do what they were ordered to do, but wu wei was the opposite of this, leaving things alone, letting Nature take her course, profiting by going with the grain of things instead of going against it, and knowing how not to interfere. 
-  I remember during the war I had a friend in the Foreign Office in London who had a huge Chinese scroll beside his desk, with these two characters alone on it, and later when later on I became Master of Caius , I found that it was essentially a practical dictum; things worked better if you left the College Lecturers, the Dean and Chaplain and the Kitchen Office to get on with it without any interference from above.
Wu wei was the great Taoist watchword throughout the ages, the untaught doctrine, the wordless edict.  It was summarised in that numinous group of phrases which Bertrand Russell collected from his time in China, ‘production without possession, action without self-assertion, development without domination. 
-  See SCC, vol 2, p. 564.
- [5S] SCC, vol. 2, p. 164: from Bertrand Russell, The Problem of China (1922), p. 194.
Now wu wei, the lack of interference, might very well be applied to a respect for the ‘automotive’ capacity of the individual farmers and their peasant communities. Even when the old ‘Asiatic’ society had given place to ‘bureaucratic feudalism’ such conceptions remained very much alive in Chinese political practice and government administration that had been inherited from ancient Asian society and from the single pair of opposites, ‘villages-princes’.
Thus, all through Chinese history, the best magistrate was he who intervened least in society’s affairs, and all through history, too, the chief aim of clans and families was to settle their affairs internally without having recourse to the courts. [p. 16, editorial paragraphing added]
-  An aspect of the darker side of this is given in the partly autobiographical account of my old friend Kuo Yu-Shou (1963).
It seems probable that a society like this would be favourable to reflection upon the world of Nature. Man should try to penetrate as far as possible into the mechanisms of the natural world and to utilise the sources of power which it contained while intervening directly as little as possible, and utilising ‘action at a distance’.[pp. 16-17, editorial paragraphing added]
Conceptions of this kind, highly intelligent, sought always to achieve effects with an economy of means,  and naturally encouraged the investigation of Nature for essentially Baconian reasons. Hence such early triumphs as those of the seismograph, the casting of iron, and water-power. 
-  One can see what this implies by imagining a city on the side of a hill above a river, where water was needed for the upper streets. The Confucians would have had squads of men pedalling square-pallet chain-pumps to send up the water from the river; but the Taoist way would have been quite different. They would have taken off a derivate canal from the river at a higher level and by guiding it along the contours, they would have reached the upper streets of the city on a wu wei principle.
-  One might add the magnetic compass, deep borehole drilling, and the escapement of clockwork, and many other inventions listed below.
It might thus be said that this non-interventionist conception of human activity was, to begin with, propitious for the development of the natural sciences. For example, the predilection for ‘action at a distance’ had great effects in early wave-theory, the discovery of the nature of the tides, the knowledge of relations between mineral bodies and plants as in geo-botanical prospecting, or again in the science of magnetism
It is often forgotten that one of the fundamental features of the great breakthrough of modern science in the time of Galileo was the knowledge of magnetic polarity, declination, etc.; and unlike Euclidean geometry and Ptolemaic astronomy, magnetical science was a totally non-European contribution.  Nothing had been known of it to speak of in Europe before the end of the 12th century, and its transmission from the earlier work of the Chinese is not in doubt. If the Chinese were (apart from the Babylonians) the greatest observers among all ancient peoples, was it not perhaps precisely because of the encouragement of non-interventionist principles, enshrined in the numinous poetry of the Taoists on the ‘water symbol’ and the ‘eternal feminine? 
-  See Needham (1960a).
-  Cf. SCC vol. 2, p. 57.
However if the non-interventionist character of the ‘villages-prince’ relationship engendered a certain conception of the world which was propitious to the progress of science, it had certain natural limitations. It was not congruent with characteristically occidental ‘interventionism’, so natural to a people of shepherds and sea-farers. Since it was not capable of allowing the mercantile mentality a leading place in the civilisation, it was not capable of fusing together the techniques of the higher artisanate with the methods of mathematical and logical reasoning which the scholars had worked out, so that the passage from the Vincian to the Galilean stage in the development of modern natural science was not achieved, perhaps not possible.[p. 17]
In medieval China there had been more systematic experimentation than the Greeks had ever attempted, or medieval Europe either;  but so long as ‘bureaucratic feudalism’ remained unchanged, mathematics could not come together with empirical Nature-observation and experiment to produce something fundamentally new. The suggestion is that experiment demanded too much active intervention, and while this had always been accepted in the arts and traqes, indeed more so than in Europe, it was perhaps more difficult in China to make it philosophically respectable.[pp. 17-18]
-  Nathan Rosenberg has suggested to us that a new attitude almost of deference to experimental results arose in Europe from the 16th century onwards, with the dominance of the bourgeoisie. which was not paralleled elsewhere. This attitude is very similar to that of merchants interested in quantitative accounting. See Rosenberg & Birdzell (1986).
There was another way, also, in which medieval Chinese society had been highly favourable to the growth of the natural sciences at the pre-Renaissance level. Traditional Chinese society was highly organic, highly cohesive.
The State was responsible for the good functioning of the entire society, even if this responsibility was carried out with the minimum intervention. One remembers that the ancient definition of the Ideal Ruler was that he should sit simply facing the south and exert his virtue (i.e. 德) in all directions so that the Ten Thousand Things would automatically be well governed. As we have been able to show over and over again, the State brought powerful aid to scientific research.  Astronomical observatories, for example, keeping millennial records, were part of the civil service; vast encyclopaedias, not only literary but also medical and agricultural, were published at the expense of the State, and scientific expeditions altogether remarkable for their time were successfully accomplished (one thinks of the early +8th-century geodetic survey of a meridian arc stretching from Indo-China to Mongolia, and of the southern hemisphere to within twenty degrees of the south celestial pole). 
-  SCC, vols 2, 3, 4, 5, 6 passim.
-  See Beer, Ho Ping-Yü, Lu Gwei-Djen, Needham, Pulleyblank & Thompson, ‘An Eighth-Century Meridian Line; I-Hsing’s Chain of Gnomons and the Pre-History of the Metric System’ (1964).
The writing by Joseph Needham is in the book General Conclusions and Reflections. The section (a) Science and Society in East and West has a sourcing footnote.
-  First published in the J. D. Bernal Presentation Volume (London, 1964), and then in Science and Society (1964) 28, 385, and Centaurus (1964), 10, 174; collected in The Grand Titration (Allen & Unwin, London, I969), and further revised for publication here.
Needham, Joseph. 2004. “General Conclusions and Reflections.” In The Social Background, edited by Kenneth Girdwood Robinson. Vol. VII:2. Science and Civilisation in China. Cambridge University Press. Online archive at https://archive.org/stream/ScienceAndCivilisationInChina/Science_and_Civilisation_in_China_Vol_7-2_General_Conclusions_and_Reflections