Today, of course, Malthus is best-remembered for his "Essay on the Principle of Population," and its argument that population grows geometrically, while food supply runs into diminishing returns, and so near-starvation was inevitable. Ricardo is best-remembered for his rigorous exposition of the principle of comparative advantage, which remains one of the most powerful non-obvious insights that economics can offer. But in their time, Malthus was what we would today call a Keynesian and Ricardo was what we might call a neoclassical economist. Indeed, John Maynard Keynes in the General Theory gives generous credit to Malthus as his predecessor for having formulated a theory of "gluts," or what we would today call recessions.
Malthus and Ricardo apparently met around 1813 in a dispute over the "corn laws," a protectionist policy of import tariffs and export subsidies that sought to benefit English farmers. Ricardo was opposed; Malthus was in favor. But in arguing it out, they jointly developed a theory of rent; a theory of how national income would be distributed among workers, merchants, and landed gentry; and thus a basis for growth theory. They wrote copious letters to each other and published pamphlets. Dorfman writes: "They labored together to understand the economic consequences of the Corn Laws. Their discussions led them to a deeper understanding of economics than anyone had attained before. But they could not agree on the substantive matter of policy."
The English economy then suffered a postwar depression after the battle of Waterloo, which led Malthus to take the Keynesian position of explaining that if saving was too high and demand too low, the economy might suffer unemployment, while Ricardo argued that overproduction could only be a temporary state of affairs. This was followed by another dispute over the ultimate source of value, in which Malthus argued for a labor-based theory of value and Ricardo argued for a cost-of-production based theory. Many more letters followed, along with copious paragraph-by-paragraph criticisms of each others' pamphlets and books. And yet Malthus and Ricardo were best friends. Dorfman writes:
"They were still at it on August 31, 1823, when Ricardo was beginning to suffer severe headaches from an abscess on his brain. On that day, Ricardo wrote Malthus a long letter, which began, "I have only a few words more to say on the subject of value, and I have done." After about two pages of careful reasoning, he concluded, "And now, my dear Malthus, I have done. Like other disputants, after much discussion we each retain our own opinions. These discussions, however, never influence our friendship; I could not like you more than I do if you agreed in opinion with me. Pray give Mrs. Ricardo's and my kind regards to Mrs. Malthus. Yours truly ..."
"Two weeks later, Ricardo was dead. At his funeral, Malthus is reported to have said, "I never loved anybody out of my own family so much. Our interchange of opinions was so unreserved, and the object after which we were both enquiring was so entirely the truth and nothing else, that I cannot but think we sooner or later must have agreed."Malthus and Ricardo laid down some challenges worth considering in one's own life. Do you go the extra distance in at least a spirit of collegiality, to explain your views? Do you try just as hard to hear validity in the criticisms of others as you do to explaining your own views? Do you leave open the possibility that your own views are only an imperfect approximation of truth, just as the views of others are an imperfect approximation of truth, so that perhaps you are searching for answers together, rather than opposing each other? Can you completely disagree but still be friends?
Here's the last word from Dorfman:
"It is as though each served as the anvil for the other's hammer, and their ideas were hammered out in their efforts to persuade each other. They were two men obsessed by a common enthusiasm, tirelessly pursuing a common goal: to understand the economy. But they did not share a common vision of the good society and thus were condemned to wrestle interminably, though remarkably fruitfully, over the roles of the social classes. Their struggles to convey to each other their views of the forces that drove their economy are an inspiring case study in both the difficulty and the possibility of human communication. These two friends, sustained by enormous affection and respect for one another, never could nullify the differences in preconception and mental style that separated them, but still could help each other attain a deeper understanding of their economy than anyone had achieved before. To do this required invincible faith in each other's candor and open-mindedness, great patience, inexhaustible good will, and unflagging civility."In the 21st century, it's useful to remember that social media snarkiness and flame wars are a choice, and other choices are possible.