Some years ago the "white goods' manufacturer Zanussi used to advertise its products as "the appliance of science". (Since "application" was evidently meant, I take it there was also a feeble allusion, exploited for the sake of the rhyme, to the notion of a "domestic appliance".) Zanussi's catchphrase might seem a plausible enough definition of technology, at least to anyone unfamiliar with Lewis Wolpert's book The Unnatural Nature of Science (1992). I mention Wolpert here, not because his observations are crucial to my argument, but merely for their intrinsic interest and obvious truth, to the effect that historically most technology, for example that of ancient China, derived from no genuinely scientific knowledge, simply because there was no such thing. However sophisticated it may have been, ancient Chinese technology was fundamentally serendipitous, empirical or ad hoc. (Thus much Wolpert.)