I really enjoyed this biography. I realize that until now I didn't know who A. von Humboldt was and the importance of his scientific work on other scientists, expecially Darwin. Each one of these scientists and men, von Humboldt, Darwin, Muir, Marsh,...loved nature almost more than themselves and their relatives. Nowadays how many people love nature the same way, more than gain, wealth and money? We really should think about it.