Although he obviously had a great intellect, his amazing curiousity is what strikes us at TinyMinds about Charles Darwin. That passionate desire to understand the natural world led him to collect hundreds of species of beetles while studying at Cambridge, and then to undertake his five-year voyage on HMS Beagle as naturalist. On that trip, he formed his ideas about natural selection while observing the different species on different islands of the Galapagos.
Darwin strove for the truth in the face of opposition to his theories when he returned home, and his writings now form the basis of our understanding of evolution.
Truly, the father of natural sciences.