I asked ChatGPT to write a letter in response. It did quite a decent job (but note the em dashes!).
Sir,
Mr Pennington mistakes the purpose of a crossword. The satisfaction lies not in demonstrating the totality of one’s existing knowledge, but in exercising curiosity, deduction and persistence. Dictionaries and encyclopaedias have long been trusted companions of the crossword enthusiast, not because they provide answers, but because they help confirm, refine or extend one’s understanding. Few would suggest that a botanist is cheating by consulting a flora or a historian by checking an archive.
The same principle applies, with appropriate caution, to newer tools. A reference work—whether printed, digital or AI-assisted—is no substitute for the solver’s reasoning. It merely offers another means of exploring language once the intellectual work has begun.
If Mr Pennington prefers to rely solely on memory, that is an admirable personal challenge. But it should remain exactly that: a personal challenge, not the standard by which everyone else’s enjoyment is judged.
Yours faithfully,