David Ricardo and T. R. Malthus shared an endearing friendship despite a contentious divergence of opinion on many political economic issues. This volume contains the formal remnants of their differences. Ricardo analyses, issue-by-issue, his points of divergence to Malthus's 'Principles of Political Economy'. Malthus's contributions to political economics generally concern his bleak forecast that a geometrically growing population would surpass the arithmetically growing capacity of essential natural resources.