Few voyages could have had such a profound effect as darwin's five-year stint on the H.M.S. Beagle. A novice naturalist on his departure in 1831, he returned a mature scientist with the set of basic ideas that were to prove truly revolutionary not only in biology but also in human affairs generally. If Galileo had shown that humankind was not at the center of the universe, Darwin was to demonstrate that humans were not the be-all and end-all of creation. Yet, as great oaks from small acorns grow, so Darwin's monumental ideas developed from his localized studies. For instance, while on his travels along the coast of South America with the H.M.S. Beagle, Darwin witnessed a volcano erupt and was literally shaken by an earthquake. He recorded in eloquent detail the physical effects of such natural upheavals and their geological implications. However, he reserved his most telling description for the effect that these events had on his philosophical state of mind – “a bad earthquake at once destroys our oldest associations: the earth, the very emblem of solidity, has moved beneath our feet like a thin crust over a fluid; one second of time has created in the mind a strange idea of insecurity which hours of reflection would not have produced.”