This book continues the series on Russian philosophy of the first half of the 20th century. So far twenty two volumes have been published in the series. The current volume includes works presenting the logico-gnoseological school in Russian philosophy associated with three scholars: M.I. Karinskii (1840-1917), V.N. Ivanovskii (1867-1939), N.A. Vasil"ev (1880-1940). Some of their works, like the one on "imaginative logic by Vasil"ev were ahead of the other scholars in this field in the world. Bibliographical references.