Aleksei Aleksandrovich Kozlov, the Russian personalist philosopher, was the first major Russian exponent of a pluralistic idealism derived from Gottfried Wilhelm Leibniz. In his youth Kozlov studied the social sciences and was attracted to the ideas of Ludwig Feuerbach and François Marie Charles Fourier. His socialist views led to a short prison term in 1866 and the loss of his teaching position in a Moscow secondary school. He began to study philosophy seriously only in the 1870s, when, after an initial interest in materialism, he came successively under the influence of Arthur Schopenhauer, Eduard von Hartmann, and Immanuel Kant. In 1876 he became professor of philosophy at Kiev University, where he published the first Russian philosophical journal, Filosofskii trekhmesiachnik (Philosophical quarterly), and began to formulate his own mature position under the influence of Leibniz and his followers—notably Gustav Teichmüller. When illness...