The ‘religious atheist’ author held a reputation as CS Lewis’s opposite. But his two trilogies – which came to a close this year – were a celebration of humanity and imagination

Twenty years ago, I visited the Botanic Garden in Oxford for the first time. Among the winding pathways lined with flowers, about halfway back, stood a bench under a tree, largely identical to the others throughout the park. Was this the one? I wondered.

I didn’t have to question it for long. A closer look revealed words and images etched along its wooden slats, all along similar lines: “Lyra + Will”, they said. Or: “Pantalaimon” and “Kirjava”. Tucked between the bench’s arm and seat was a folded-up scrap of paper with a handwritten message of thanks.