Value and Dialectic in Marx

I find it difficult to agree with Garegnani's assertion that for Marx the role of labor value is "merely" to provide a noncircular determination of the rate of profit and of prices. Vianello and Lippi have shown elsewhere that this thesis is untenable. I would like to add a few elementary considerations of my own in further support of their arguments. Let me begin with Marx's comment on chapter 6 of Book I of Adam Smith's Wealth of Nations (see Theories of Surplus Value, vol. 1, pp. 186-198). The outline of the argument is as follows: The amount of value that wage labor adds to raw materials divides in two parts. One is the value of labor power: namely, wages. The other becomes what Smith calls profit and what Marx calls surplus value. With this second component of value, the capitalist entrepreneur pays "interest" to those who advanced money to him and "ground rent" to the owner of the land on which he has located his enterprise. What remains is "profit" in the strict sense. The argument is simple but eloquent. It gives us the anatomy of modern bourgeois society (which is what Marx