Dialectical materialism was initially expounded by Karl Marx and Friedrich Engels; one of the early works on the subject is Engel's 1878 polemic "Anti-Dühring". It was elaborated by Vladimir Lenin in "Materialism and Empiriocriticism" (1908) around three axes: the "materialist inversion" of Hegelian dialectics; the historicity of ethical principles ordered to class struggle; and the convergence of "laws of evolution" in physics (Helmholtz), biology (Darwin) and political economy (Marx). Lenin hence took position between a historicist Marxism (Labriola) and a determinist Marxism, close to what was later called "social Darwinism" (Kautsky). Lenin's most important philosophical rival was Alexander Bogdanov (1873–1928), who tried to synthesize Marxism with the philosophies of Ernst Mach, Wilhelm Ostwald, and Richard Avenarius (which were harshly criticized in Lenin's "Materialism and Empiriocriticism"). Bodganov wrote a treatise on "tectology" and was one of the founders of Proletkult after the First World War.