I was writing late last night and, on re-reading what I had written became aware of an odd juxtaposition of certain words. They took me straight back to a book where a particular passage had left its mark. There was no thought of copying; no intent to re-use or appropriate the work of another writer, and what I had noticed was no more than three words long. Perhaps it was the context rather than the phrase that had been the reminder. Even so, it got me thinking.

With all the words that have been written by the human hand over the millennia, are there any that have been left unsaid? Can we ever write without plagiarising, consciously or unconsciously the work of another who has gone before? I remember reading once that Shakespeare had summarised every human emotion in his work. That is open to debate, of course, and the…