If Pan may be understood as Lyra’s consciousness, by the second book in the trilogy they are not on good terms, a familiar tension to anyone who has experienced an alienation of the self with the arrival of adulthood. Lyra is in thrall to the chilly doctrines of two philosophers who insist on the validity of rationality to the exclusion of everything else, and believe that truth is a subjective fancy, as dogmatic in their way as the Magisterium are in theirs. Pan can see the danger in this, that the power they offer will deprive Lyra of something essential to her being, stifling creativity, delight and liberty.

It confirms what I took from the first trilogy, that the enemy is not God, but the dogmatic, and the peculiar treason of clerks trading in irreducible freedom for manageable powers. Pullman writes about this with a tone of angry lament that recalls Blake, one of his literary heroes, and when the Magisterium arrives, I often think of priests in black gowns binding joys and desires; or sometimes, General Synod. But the philosophers of reason and relativism also have designs on our joys and desires and one wonders what Blake would have made of those in the vanguard of that ambitious project.

Pullman’s prose is deeply rooted in English literature. In it, you hear echoes of Blake, Spenser and Milton, and behind them, not faintly to my ear, the English of the Authorised Version and the Book of Common Prayer. There is a grain running through his writing, of liveliness and a sort of lopsided loveliness, that I trace back to those sources.

That connection comes not only from Pullman’s language but also from his sense of liberty, freeing Scripture and liturgy from the exclusive authority of the clergy by putting them into the vernacular, and the hearts and minds and hands of the people. Thanks be to God.

The Book of Dust is in preview at the Bridge Theatre, London SE1, (0333 320 0051; bridgetheatre.co.uk). The Rev Richard Coles’s latest book is The Madness of Grief (W&N, £16.99)