Other naturalists were critical of Diluvialism: the Church of Scotland pastor John Fleming published opposing arguments in a series of articles from 1823 onwards. He was critical of the assumption that fossils resembling modern tropical species had been swept north "by some violent means", which he regarded as absurd considering the "unbroken state" of fossil remains. For example, fossil mammoths demonstrated adaptation to the same northern climates now prevalent where they were found. He criticized Buckland's identification of red mud in the Kirkdale cave as diluvial, when near identical mud in other caves had been described as fluvial.[5] While Cuvier had reconciled geology with a loose reading of the biblical text, Fleming argued that such a union was "indiscreet" and turned to a more literal view of Genesis:[30]

But if the supposed impetuous torrent excavated valleys, and transported masses of rocks to a distance from their original repositories, then must the soil have been swept from off the earth to the destruction of the vegetable tribes. Moses does not record such an occurrence. On the contrary, in his history of the dove and the olive-leaf plucked off, he furnishes a proof that the flood was not so violent in its motions as to disturb the soil, nor to overturn the trees which it supported.

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."[8] He was a close associate of Robert Edmond Grant, who considered that the same laws of life affected all organisms.

In 1824, Fleming became involved in a famous controversy with the geologist William Buckland (1784–1856) about the nature of The Flood as described in the Bible. In 1828, he 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.[9]

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.

Partial list of publications

• 1821: Insecta in Supplement to the fourth, fifth and sixth editions of the Encyclopae-dia Britannica, with preliminary dissertations on the history of the sciences

• 1822: Philosophy of Zoology (Volume 1, Volume 2)

• 1828: A History of British animals, exhibiting the descriptive characters and systematical arrangement of the genera and species of quadrupeds, birds, reptiles, fishes, mollusca, and radiata of the United Kingdom, including the indigenous, extirpated , and extinct kinds, together with periodical and occasional visitants Edinburgh: i–xxiii + 1–565.

• 1837: Molluscous Animals

• 1851: The Temperature of the Seasons, and Its Influence on Inorganic Objects, and on Plants and Animals