This chapter discusses the biography of the following philosopher: K. D. Kavelin, P. L. Lavrov, N. K. Mikhailovski, N. I. Kareyev. Among them it mainly focuses on the biography of P. L. Lavrov. Lavrov grew up in approximately the same spiritual environment as Chernyshevski. For him, as for Chernyshevski, the scientific spirit and scientific criticism provided the basic and defining principles of knowledge and creative activity. Lavrov's semi-positivism lies in his acceptance of the independence of the ethical sphere, a sphere which is unanalysable and non-deducible from facts. Lavrov himself expressed the basic position of philosophic anthropologism in the three following principles: (1) the reality of individual consciousness (2) the principle of realism and (3) the sceptical principle. At first Lavrov's anthropologism was directly related to his critical philosophy and his positivism a combination of the ideas of Kant and Comte; but, in the end, it unexpectedly appeared as an ethical immanentism.