Once regarded as the leading figure among the Left Hegelians in the 1840s, Ludwig Feuerbach (1804-1872) is remembered today chiefly for his influence on the young Karl Marx, and, as the author of The Essence of Christianity . This study treats Feuerbach's philosophy as compelling in its own right and examines it critically against the work of other nineteenth century thinkers, specifically Hegel, Stirner, Marx and Nietzsche. Feuerbach's synthesis of naturalism, humanism and materialism into an ontology of human species-being ( Gattungswesen ) is traced through his works. Finally, the implications of Feuerbach's species-ontology for our social and political being are drawn; on this basis the study argues for a re-acquaintance of Feuerbach's work.