Thomas Henry Huxley

Thomas Henry Huxley (Ealing, 1825 – Eastbourne, 1895) was a British biologist specialised in comparative anatomy, known as "Darwin's Bulldog" for his public defence of the theory of evolution. He lived in the Victorian era, when Britain was debating with growing intensity the relationship between science and religion. His importance lies both in his research and in his role in gaining acceptance for Darwinism and in reforming science teaching.

Huxley had very little formal schooling. The son of a mathematics teacher whose school closed and left the family in financial trouble, he left school at ten. Still, he set out to educate himself: he taught himself German, Latin and enough Greek to read Aristotle in the original. At seventeen he began medical studies at Charing Cross Hospital, where he was taught by Thomas Wharton Jones. In 1845 he published his first scientific paper, describing a layer of the hair follicle that had gone unnoticed and that still bears his name. He passed the first medical examination of the University of London but never completed the degree. He then joined the Royal Navy as surgeon on HMS Rattlesnake, which sailed to New Guinea and Australia between 1846 and 1850.

On that voyage Huxley studied marine invertebrates, above all jellyfish and polyps. From his observations came the class Hydrozoa, grouping animals built from two tissue layers around a central cavity, a body plan now characteristic of the cnidarians. His 1849 paper earned him election to the Royal Society in 1850, and there he formed lasting friendships with Joseph Dalton Hooker and John Tyndall. He later clarified the place of appendicularians and ascidians, which are tunicates related to the vertebrates.

In 1854 he left the navy and took the chair of natural history at the School of Mines in London, a post he held for more than thirty years. There he worked mainly on fossil fish and reptiles and proposed the group Sauropsida to unite reptiles and birds. His 1858 lecture on the vertebrate skull put him in opposition to Richard Owen, and he also debated with Owen the relationship between humans and apes, set out in 1863 in Evidence as to Man's Place in Nature. He later argued that birds descended from small carnivorous dinosaurs, a view widely accepted today.

His most famous moment came at the British Association meeting in Oxford in June 1860, where he faced Bishop Samuel Wilberforce. The popular account of that exchange, including the well-known question about ancestry, may have been embellished over time, but the episode helped establish him as Darwin's public champion. Privately Huxley had doubts about some Darwinian points, such as gradualism and natural selection, yet he defended Darwin's work firmly. In 1869 he coined the word "agnostic" to describe a stance that neither asserts nor denies what cannot be known, and he developed the idea further in later writings.

His public activity was just as wide. He sat on many royal commissions, served as secretary and later president of the Royal Society, presided over the British Association in 1870 and joined the London School Board. He argued for a broad science education in schools, with general study in primary years and more specialised work later. His essay "On a Piece of Chalk" (1868) showed how the geological history of Britain can be read in a piece of chalk and presented scientific method as organised common sense. Until his death in Eastbourne in 1895 he remained a central figure in British science, and he was grandfather of Aldous Huxley and of Julian and Andrew Huxley, part of a family of scientists and writers.