Historian William Mackay Mackenzie published his thoughts in the "Scotsman" letters pages (8 October 1921) as part of a long-running debate arising from D. A. Mackenzie's lecture in 1920. While agreeing there had been a "sporadic prejudice" against pork in parts of Scotland, and offering illustrations of this, he was against the idea of a link to a "religious cult". He saw economic factors at work between 1500 and 1800 which would discourage pig-keeping. He cited several examples of pork consumption in the Middle Ages, and described a "temporary lapse" when "the great forests disappeared from Scotland".