Karl Marx wrote a lot about David Ricardo's economics. Here is some of what he had to say in Theories of Surplus Value:
Ricardo starts out from the determination of the relative va1ues (or exchangeable values) of commodities by “the quantity of labour”. (We can examine later the various senses in which Ricardo uses the term value. This is the basis of Bailey’s criticism and, at the same time, of Ricardo’s shortcomings.) The character of this “labour” is not further examined, If two commodities are equivalents—or bear a definite proportion to each other or, which is the same thing, if their magnitude differs according to the ||524| quantity of “labour” which they contain—then it is obvious that regarded as exchange-values, their substance must be the same. Their substance is labour. That is why they are “values”. Their magnitude varies, according to whether they contain more or less of this substance. But Ricardo does not examine the form—the peculiar characteristic of labour that creates exchange-value or manifests itself in exchange-values—the nature of this labour. Hence lie does not grasp the connection of this labour with money or that it must assume the form of money. Hence he completely fails to grasp the connection between the determination of the exchange-value of the commodity by labour-time and the fact that the development of commodities necessarily leads to the formation of money. Hence his erroneous theory of money. Right from the start he is only concerned with the magnitude of value, i.e., the fact that the magnitudes of the va1ues of the commodities are proportionate to the quantities of labour which are required for their production. Ricardo proceeds from here and he expressly names Adam Smith as his starting-point (Chapter I, Section I).
Ricardo’s method is as follows: He begins with the determination of the magnitude of the value of the commodity by labour-time and then examines whether the other economic relations and categories contradict this determination of value or to what extent they modify it. The historical justification of this method of procedure, its scientific necessity in the history of economics, are evident at first sight, but so is, at the same time, its scientific inadequacy. This inadequacy not only shows itself in the method of presentation (in a formal sense) but leads to erroneous results because it omits some essential links and directly seeks to prove the congruity of the economic categories with one another.
Historically, this method of investigation was justified and necessary. Political economy had achieved a certain comprehensiveness with Adam Smith; to a certain extent he had covered the whole of its territory, so that Say was able to summarise it all in one textbook, superficially but quite systematically. The only investigations that were made in the period between Smith and Ricardo were ones of detail, on productive and unproductive labour, finance, theory of population, landed property and taxes. Smith himself moves with great naïveté in a perpetual contradiction. On the one hand he traces the intrinsic connection existing between economic categories or the obscure structure of the bourgeois economic system. On the other, he simultaneously sets forth the connection as it appears in the phenomena of competition and thus as it presents itself to the unscientific observer just as to him who is actually involved and interested in the process of bourgeois production. One of these conceptions fathoms the inner connection, the physiology, so to speak, of the bourgeois system, whereas the other takes the external phenomena of life, as they seem and appear and merely describes, catalogues, recounts and arranges them under formal definitions. With Smith both these methods of approach not only merrily run alongside one another, but also intermingle and constantly contradict one another. With him this is justifiable (with the exception of a few special investigations, [such as] that into money) since his task was indeed a twofold one. On the one hand he attempted to penetrate the inner physiology of bourgeois society but on the other, he partly tried to describe its externally apparent forms of life for the first time, to show its relations as they appear outwardly and partly he had even to find a nomenclature and corresponding mental concepts for these phenomena, i.e., to reproduce them for the first time in the language and [in the] thought process. The one task interests him as much as the other and since both proceed independently of one another, this results in completely contradictory ways of presentation: the one expresses the intrinsic connections more or less correctly, the other, with the same justification—and without any connection to the first method of approach—expresses the apparent connections without any internal relation. Adam Smith’s successors, in so far as they do not represent the reaction against him of older and obsolete methods of approach, can pursue their particular investigations and observations undisturbedly and can always regard Adam Smith as their base, whether they follow the esoteric or the exoteric part of his work or whether, as is almost always the case, they jumble up the two. But at last Ricardo steps in and calls to science: Halt! The basis, the starting-point for the physiology of the bourgeois system—for the understanding of its internal organic coherence and life process—is the determination of value by labour-time. Ricardo starts with this and forces science to get out of the rut, to render an account of the extent to which the other categories—the relations of production and commerce—evolved and described by it, correspond to or contradict this basis, this starting-point; to elucidate how far a science which in fact only reflects and reproduces the manifest forms of the process, and therefore also how far these manifestations themselves, correspond to the basis on which the inner coherence, the actual physiology of bourgeois society rests or the basis which forms its starting-point; and in general, to examine how matters stand with the contradiction between the apparent and the actual movement of the system. This then is Ricardo’s great historical significance for science. This is why the inane Say, Ricardo having cut the ground from right under his feet, gave vent to his anger in the phrase that “under the pretext of expanding it” (science) “it had been pushed into a vacuum”. Closely bound up with this scientific merit is the fact that Ricardo exposes and describes the economic contradiction between the classes—as shown by the intrinsic relations—and that consequently political economy perceives, discovers the root of the historical struggle and development. Carey (the passage to be looked up later) therefore denounces him as the father of communism.
I find the following, at least, of interest in this long passage:
- Marx here writes about "the connection as it appears in the phenomena of competition", "the external phenomena of life, as they seem and appear", "externally apparent forms of life". I think these phrases echo what Marx elsewhere describes as "vulgar political economy", commodity "fetishism", and the "illusions" created by competition.
- Marx criticizes Ricardo for only being concerned with "the magnitudes of values of commodities", not with the "peculiar character of labour that ... manifests itself in exchange values". I think this supports those who do not see a (great) contradiction between volumes 1 and 3 of Capital.
- Marx talks about the connection of labor values with money. I like interpretations or solutions of Marx's transformation problem that relate value to some abstract measure of the value of the output of a capitalist economy, namely:
- Those based on Sraffa's standard commodity
- Foley and Duménil's new interpretation, which focuses on the Monetary Expression of Labor Time (MELT).
- I quite like that "Halt!" I think it fair to say that Marx saw himself following and transcending Ricardo in exploring "the obscure structure of the bourgeois economic system", "the intrinsic relations", "the inner coherence, the actual physiology of bourgeois society".