The Week In Radio: The trouble with history and 'Citizen Kane'

Last week, I came across a review of a book on the plague that devastated Europe and the near East between the sixth and eighth centuries. The what, you say? Well, quite: for centuries, this plague was all but forgotten: we know all about the Black Death, but this plague, which may have been far greater, which decimated cities, wiped out thousands of villages, killed millions, vanished from view.

Which shows how fragile knowledge is, and how random our view of history. Two programmes on Thursday raised the subject. On In Our Time (BBC Radio 4), Melvyn Bragg was discussing the Library of Nineveh, a vast collection of writings assembled in the seventh century BC by the Assyrian king Ashurbanipal. The library – not far from the modern Iraqi city of Mosul – was stumbled upon in 1849 by Austen Henry Layard, a young British dabbler in archaeology who can't have had much idea of the importance of what he had found. It contained millions of cuneiform tablets – little clay pillows, anything from 1cm to 25cm in size, stamped with wedge-shaped marks, the alphabet of the time. Most of the tablets dealt with the business of government, though since, in ancient Assyria, that included divination and doing the right things by the gods, they weren't necessarily as dry as all that.

The tablets also included the epic of Gilgamesh, which may be the earliest story known, and tales of a great flood, prefiguring the biblical story. The flood story is itself a parable of the fragility of knowledge – before the flood, fish-people who slept in the ocean by night acted as intermediaries between mankind and the gods, and taught us everything that is useful; but the flood put a stop to that.

The abundance of cuneiform fragments gave scholars the chance to start decoding them: and since cuneiform was the main alphabet for a slew of civilisations for around 3,000 years, that in turn made vast areas of the ancient world intelligible for the first time. But it was luck – the library might easily not have survived, or have been found by people who weren't interested in preserving its contents. It's peculiar, when you look at it, that we have any sense of history at all – that we don't just live in the bubble of the recent past, the stuff we can remember without looking it up.

And even the recent past is a chancy proposition. The Man from the McCarthy Agency (BBC Radio 4) told of the discovery of a vast archive of film reviews, written between the 1930s and the 1960s by Harold McCarthy. These reviews were never actually published: McCarthy ran an agency advising cinema owners on which films were likely to sell to the public. His system of categorising cinemas as "better class", "popular halls" and "industrial" now seems quaintly snobbish, and many of his judgements are at odds with mainstream opinion (Citizen Kane had "little to recommend it outside of the specialised hall"), but they stand now as correctives to critical orthodoxy, and a strong reminder that the history of cinema doesn't necessarily have much to do with what most people see and remember.

Hearing Matthew Sweet's jolly and intelligent account, you felt pleased that McCarthy's work had survived, and pleased that somebody had bothered to tell us about it.