Thomas Henry Huxley (4 May 1825 – 29 June 1895) was an English biologist specialising in comparative anatomy. He is known as "Darwin's Bulldog" for his advocacy of Charles Darwin's theory of evolution.Huxley's famous debate in 1860 with Samuel Wilberforce was a key moment in the wider acceptance of evolution and in his own career. Huxley had been planning to leave Oxford on the previous day, but, after an encounter with Robert Chambers, the author of Vestiges, he changed his mind and decided to join the debate. Wilberforce was coached by Richard Owen, against whom Huxley also debated about whether humans were closely related to apes.
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There is a well-worn adage that those who set out upon a great enterprise would do well to count the cost. I am not sure that this is always true. I think that some of the very greatest enterprises in this world have been carried out successfully simply because the people who undertook them did not count the cost; and I am much of the opinion that . . . the most instructive consideration for us is the cost of doing nothing.