Those individuals which took the greatest pleasure in society would best escape various dangers; while those that cared least for their comrades and lived solitary would perish in greatest numbers. The very idea of humanity, as far as I could observe, was new to most Gauchos of the Pampas. This virtue, one of the noblest which man is endowed, seems to arise incidentally from our sympathies becoming more tender and more widely diffused, until they are extended to all sentient beings. As soon as this virtue is honored and practiced by some few men, it spreads through instruction and example to the young, and eventually through public opinion
Charles Darwin