Joel, a loyal MR reader, asks me:
I am an undergraduate economics student curious about which of the classical economists and books you find most valuable. Classical not just meaning Ricardian but in terms of significant non purely quantitative works that influenced economics as a whole. If one were to put together a reading list of twenty or so of the most influential or important books, what would you recommend? The Wealth of Nations and General Theory of Employment, Interest, and Money seem logical starting points, beyond them though it's hard to wade through the range of choices (Ricardo or Hayek? Schumpeter or Jean Baptiste Say?)
For now I'll stick with classical economics in the narrow sense, as it ends in 1871. If you can read only a few works, I recommend these:
1. Adam Smith, Wealth of Nations. Duh.
2. David Hume, Economic essays. He lacks some of Smith's profundity as an economist, but he is more precise analytically and as always a beautiful writer.
3. David Ricardo, Principles of Political Economy, the first six chapters. Rigor arrives, though at the expense of truth. Still there is something to it. Supplement with Mark Blaug on Ricardo, if you want the model spelt out mathematically.
4. The early marginalists: I'll recommend Samuel Bailey on value and Mountifort Longfield on price theory. Yet still it was a (temporary) dead end and you should read them with that puzzle in mind. At what level of technical sophistication do the contributions of marginalism suddenly seem impressive?
5. Thomas Robert Malthus, on population (don't ask which edition) and Principles of Political Economy. He understood supply and demand, elasticity, a version of the Keynesian model, and environmental economics, and yet he is mainly criticized for being wrong about population. He is one of the strongest and most profound and most underrated economists of all time. Also read Keynes's biographical essay on him.
6. Edinburgh Review. The econ blogosphere of its day. Read the economic essays published in that outlet, by Malthus and many others, especially on monetary theory. I don't know any easy way to track this stuff down, but if you do please tell us in the comments.
7. John Stuart Mill: Autobiography (yes, for economics) and his Some Essays on Unsettled Questions in Political Economy (Kindle edition is free). Mill has underrated depth as an economic thinker and he encompassed virtually all of the interesting trends of his time. That was both his greatest strength and his biggest weakness.
8. Marx: The 1844 manuscripts. More generally, read the Romantics as critics of classical political economy. Coleridge and Carlyle are good places to start.
What about the French?: I find Say boring, Bastiat fun, Cournot incredible but there is no reason to read the original. Try someone weird like Comte or LePlay to get a sense of what economic discourse actually was like back then.