Rev Prof John Fleming DD FRSE FRS FSA (10 January 1785 – 18 November 1857) was a Scottish minister, naturalist, zoologist and geologist. He named and described a number of species of molluscs. During his life he tried to reconcile theology with science.
After his studies at the University of Edinburgh were completed in 1805, the following year he became a pastor in the Church of Scotland and was assigned to the parish of Bressay in Scotland. He was ordained in 1808. From 1808 in 1834 he served in various parishes in Scotland. In 1808, he participated in founding the Wernerian Society, a learned society devoted to the study of natural history.
John Fleming joined the Royal Society on 25 February 1813. In 1814, he became a doctor of theology at the University of St. Andrews and in the same year he became a fellow of the Royal Society of Edinburgh. In 1824, he became involved in a famous controversy with the geologist William Buckland (1784–1856) about the nature of The Flood as described in the Bible.
Fleming was a close associate of Robert Edmond Grant, who considered that the same laws of life affected all organisms. In 1828, Fleming published his History of British Animals. This book addressed not only extant, but also fossil species. It explained the presence of fossils by climate change, suggesting that extinct species would have survived if weather conditions had been favorable. These theories contributed to the advancement of biogeography, and exerted some influence on Charles Darwin (1809–1882). Flemings' comments on instinct in his book Philosophy of Zoology had influenced Darwin.
Fleming was a vitalist who was strongly opposed to materialism. He believed that a 'vital principle' was inherent in the embryo with the capacity of "developing in succession the destined plan of existence."
In 1831, Fleming found some fossils which he recognized as fish in the Old Red Sandstone units at Fife. This did not fit the generally accepted notion that the Earth was approximately 6,000 years old. He was awarded the chair of natural philosophy at the University of Aberdeen's King's College in 1834. In 1845, he became professor of natural history in New College, Edinburgh and was three times elected President of the Edinburgh Botanical Society (1847–48, 1849–50 and 1856–57).
He died at home, Seagrove House in Leith and is buried with his family in the western half of Dean Cemetery in Edinburgh. He is buried with his wife, Melville Christie (1796–1862) and son Dr Andrew Fleming (1821–1901) (also a Fellow of the Royal Society of Edinburgh) who rose to be Depute Surgeon General of the Indian Army.
Species in the phylum Mollusca described by Fleming: