The New York Times called him "the last of the giants belonging to that wonderful group of intellectuals that included, among others, Darwin, Huxley, Spencer, Lyell, and Owen, whose daring investigations revolutionised and evolutionised the thought of the century."
The New York Times menyebutnya "yang terakhir dari para raksasa dalam kalangan intelektual hebat yang antara lain meliputi Darwin, Huxley, Spencer, Lyell, dan Owen, yang penyelidikan beraninya merevolusi dan mengevolusi pemikiran abad ini."