1748, Fala, Midlothian, Scotland.
December 28, 1788, London, England.
Son of a farmer, Logan was educated at Edinburgh University. He entered the ministry of the Church of Scotland, becoming minister of South Leith in 1770.
During his time in Leith, he delivered lectures on philosophy and history with much success. While he was thus engaged, the chair of Universal History at the University became vacant, but he was unsuccessful as a candidate.
In 1775 he joined the Committee which prepared the Translations and Paraphrases of the Church of Scotland. Around 1782, he resigned his post at Leith and moved to London, where he supported himself partly by his pen.