The paper argues that, well aware of the developments in contemporary science, including biology and political economy, Dickens believed in the significance of the scientific paradigm shifts for ordinary human life. Dickensís early fiction constituted, among other things, a passionate critique of para-Malthusian political economy. This critique is resumed in Our Mutual Friend, yet with the new awareness of the shift of dominant paradigms from political economy to Darwinist biological thinking. Whereas the legislature that grew out of political economy could be challenged and modified, Darwinís account of natural selection, a biological theory that had permanent ontological ramifications, had a claim to the stability of a natural law which disabled beliefs in Providential design. Darwinís work, however, did not deny the potential of benevolent sympathetic human agency. Dickensís novel pits such agency against the blind forces of the struggle for survival, even while subverting the confidence in overall ethical design trailed in by the residual elements of the traditional melodrama.