He was the first man to sail three times around the world. Without formal training, he made enduring contributions to mapping (especially hydrography), meteorology, navigation, zoology, botany and anthropology. He originated the concept of sub-species and a case can be made that his observations of fauna on the Galapagos Islands and elsewhere anticipated Darwin's work on natural selection.
More than 1000 words in The Oxford English Dictionary, including barbecue and chopsticks, were first recorded by him. He wrote precise, vigorous prose and his best-selling accounts of adventures and discoveries at sea and on five continents (mainly in the Americas, South-East Asia, Australia and New Guinea) set a standard for travel-writing and made him a celebrity among London's intellectuals at the dawn of the Age of Reason. Swift and Defoe mined his work for much of the ore they transmuted into Gulliver's Travels and Robinson Crusoe.
Fraternally, Philip Carter / Facebook / Great is Truth and mighty above all things (I Esdras 4:41)