In the review of book of the known American writer of В. Ирвинга a critic offers the main requirement to history as to science: to explain historical events not character of historical figures, and terms of life of people. Application of this requirement to concrete material of Добролюбов demonstrates on the example of origin of islam. Indeed, естественно-историческое explanation of this phenomenon comes forward for him as psychological. Showing that founder of religion - Mahomet was the real living man, but not some evil genius, as he was drawn by christian literature, Добролюбов takes off a cover "wonderful" from the origin of religion.