In Terry Pratchett’s Lords and Ladies the wizard Ponder Stibbons has been exploring the magnetic effects of a mysterious stone circle:

“Rocks! Why am I messing around with lumps of stone? When did they ever tell anyone anything?’ said Ponder. ‘You know, sir, sometimes I think there’s a great ocean of truth out there and I’m just sitting on the beach playing with … with stones.”

Ponder, who is by temperament more of a scientist than a wizard, is inadvertently quoting Isaac Newton.

"I do not know what I may appear to the world; but to myself I seem to have been only like a boy playing on the sea-shore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me."

But perhaps there is a still more interesting allusive dynamic at work here. This novel centres around the performance of a play which is clearly the Discworld equivalent of A Midsummer Night’s Dream and Ponder’s (overt) allusion to Newton might in fact be a (more buried and covert) allusion to a very famous speech from Shakespeare’s play, itself yet another allusion.

What are the characteristics of Ponder’s words? They express a yearning for something beyond his own world couched in words which are (ironically and reflexively) a kind of message from beyond his own world – from our own – although admittedly they have been somewhat garbled in their journey to Discworld.

A similar expression of yearning and wonder in A Midsummer Night’s Dream is also expressed in words which are, like Ponder’s, an allusion to a text the character shouldn’t be able to access, not because it exists in a parallel universe but because it hasn’t yet been written.

“The eye of man hath not heard, the ear of man hath not seen, man's hand is not able to taste, his tongue to conceive, nor his heart to report, what my dream was”. (4.1.209-12)

These are Bottom’s words as he tries to articulate the wonder of his ‘dream’ encounter with Titania. They are also a confused version of Paul’s Letter to Corinthians in which he describes the power of the Holy Spirit.

The speech’s effectiveness as an allusion is not limited to the fact that both Paul and Bottom, in very different ways, are describing something beyond normal human experience. It is not simply the content of the allusion but the fact and nature of that allusion which is significant. Bottom shouldn’t be quoting from the New Testament as A Midsummer Night’s Dream is set long before the birth of Christ. Like Ponder’s quote from Newton, the Bible’s presence in ancient Athens is almost uncanny.

Both allusions, Ponder’s to Newton and Bottom’s to Paul, express an appropriately reflexive longing for hidden knowledge, other worlds. Both Bottom and Ponder are approaching the barrier which separates them from us.