Jeremy Paxman observes  that during his 16 years as host of University Challenge, he has found that contestants "know less and less about classics and the Bible, and more and more about science and computing".
Who can doubt it? But this modern lack of awareness of two fields that were regarded as essential to a good education for so long is little noted -- even though it must count as one of the greatest transformations in our culture in the past half-century.
When Enoch Powell made his infamous "rivers of blood" speech in 1968, he could have assumed that the wider audience would know that the quotation was from Virgil's Aeneid (Mary Beard analyses the reference brilliantly here ).
Similarly, Tony Benn could still be certain that a sizeable number of his potential readers would understand why he titled his 2004 memoir Dare to be a Daniel ; that they would be aware of the Old Testament prophet of that name, if not necessarily the Salvation Army hymn.
But that would have been the older proportion. For younger browsers, the first Daniel to come to mind would probably be the Harry Potter actor Daniel Radcliffe. Benn acknowledges as much in his book: "I often forget that few people now have a biblical background or knowledge of the different Christian traditions. Biblical and religious references that slip into my speeches and articles are not necessarily always understood."
To lament the passing of these corpuses of knowledge out of the realms of popular discourse and their retreat into the citadels of scholars is not to make any comment about levels of religious belief: after all, a classical education was never intended to encourage consultations with oracles or sacrifices to Zeus. It is, instead, to mourn the breaking of a connection with millennia of history, references to which were the common currency of art, literature, music and even conversation.
Is speech the poorer for our no longer being able to assume familiarity with the works of Homer and the precise gradations of office in the Roman senate? Yes, I think so. More serious, though, is that a proper understanding of much of the fine art produced in Europe over the past 2,000 years is simply not possible without knowledge of the Bible. This not just about the subject matter, but about the positioning of people, objects, shadows -- all allusions lost on those unversed in Christianity.
Likewise, the joys of Handel's Messiah or Mozart's Requiem are severely impaired if one does not know why, as the countertenor aria has it, "He was despised, despised and rejected", or what the sounding of the trumpets in the "Dies Irae" -- the Day of Judgement -- are heralding. Questions of rights, philosophy, the existence of evil -- all these matters are frequently approached afresh, which may be a good thing in itself. What is less commendable is the latter-day ignorance about the Christian and classical thinkers who spent long decades pondering and writing about them. There just might be something to be learned there.
I am not suggesting that all need attain the easy expertise in the classics of a Boris Johnson or the ability to cite Old Testament chapter and verse possessed by my late grandfather, a Methodist who frequently spent a good couple of hours debating scripture on the doorstep when Jehovah's Witnesses came to call. But for these vast libraries to slip from the mind within a generation or two, and for no one to call "Stop!" and urge us to consider what we are losing, feels like carelessness of monumental proportions.
Does it really not matter that we no longer know what, until very recently, our ancestors took for granted?