St. George Jackson Mivart (born November 30, 1827, London, England—died April 1, 1900, London) was a British biologist and a leading critic of Charles Darwin’s theory of natural selection.
Unable to enter the University of Oxford, then open only to Anglican students, after his conversion to Roman Catholicism (1844), Mivart continued his studies at St. Mary’s, Oscott (1844–46). His research into the anatomy of carnivores and insectivores, conducted while he was lecturing at the medical school of St. Mary’s Hospital (1862–84), greatly increased knowledge of the subject. In 1881 he published The Cat: An Introduction to the Study of Backboned Animals, which is considered to rank with Thomas Henry Huxley’s Crayfish for its accuracy, detail, and clarity.
Mivart supported the general concept of evolution but minimized the contribution of natural selection, preferring to believe that the appearance of new species resulted from an innate plastic power that he called individuation (a positive internal force within living beings through which they evolve). He argued that natural selection could never produce complex structures such as the vertebrate eye, because the initial stages of the structure would be useless until all the components were present. He also denied the evolution of human intellect, insisting that it was conferred by divine power. His publication of On the Genesis of Species (1871), Nature and Thought (1882), and The Origin of Human Reason (1889) alienated both Darwin and Huxley.
Mivart also fell from favor with the church. While a professor of the philosophy of natural history at the Catholic University of Leuven (Louvain) in Belgium (1890–93), he published several articles that seemed to conflict with religious teachings. These articles were placed on the Vatican’s index of forbidden writings, and further controversial articles led to Mivart’s excommunication by Cardinal Herbert Vaughan (archbishop of Westminster from 1892–1903) in 1900. Mivart died of diabetes that same year and was buried in unconsecrated ground at a cemetery in Kensal Green, London. In 1904 he was given a Catholic burial after representations were made to the church by his friends, who argued that the later inconsistency of his views had been a result of his illness.
Mivart was elected a fellow of the Royal Society (1867). A species of lizard called Emoia mivarti is named for him.