What does Marx mean when he refers to “magnitude”? Take, for example, the following passage: “Whatever their exchange relation may be, it can always be represented by an equation in which a given quantity of corn is equated to some quantity of iron, for instance 1 quarter of corn == x cwt of iron. What does this equation signify? It signifies that a common element of identical magnitude exists in two different things, in 1 quarter of corn and similarly in x cwt of iron.”
Does “magnitude” here refer to the amount of usefulness, or something else?
Thank you in advance.
Oh I see, so in “a common element of identical magnitude exists in two different things”, this is alluding to what he is building towards, which is “a certain amount of money exists which they are both equal to”. Is this correct?
Sort of. First he’s establishing barter systems where you can exchange any commodity for any other commodity, and that they have this abstract exchange-value that is more abstract than money. Then he introduces the concept of a common exchangeable commodity, because while a pound of potatoes might be worth a few yards of linen to one person, they might not be to another. This becomes the money commodity, which is the physical manifestation of exchange-value. So exchange-value precedes money. That’s why Marx doesn’t get into the money form until later