The following is part questions and part reflection on Chapter 1 Section 3A. I've really had to chew on this section, and I still don't think I've completely grasped it. All my page numbers are from the Fowkes translation.

The quote below threw me for a bit of a loop yesterday, but reading it again today and considering an earlier quote ("Now we know the substance of value. It is labour. We know the measure of its magnitude. It is labour-time. The form, which stamps value as exchange-value, remains to be analysed. But before this we need to develop the characteristics we have already found somewhat more fully." p 131), it seems like I should have expected this.

“In other words, the value of a commodity is independently expressed through its presentation [Darstellung] as 'exchange-value'. When, at the beginning of this chapter, we said in the customary manner that a commodity is both a use-value and an exchange-value, this was, strictly speaking, wrong. A commodity is a use-value or object of utility, and a 'value'. It appears as the twofold thing it really is as soon as its value possesses its own particular form of manifestation, which is distinct from its natural form. This form of manifestation is exchange-value, and the commodity never has this form when looked at in isolation, but only when it is in a value-relation or an exchange relation with a second commodity of a different kind. Once we know this, our manner of speaking does no harm; it serves, rather, as an abbreviation.” (Marx et al., 1981, p. 152)

Before this, I had loosely defined "value" as a concept quite separate from "exchange-value", perhaps by conflating exchange-value and price in a way that I should not have (as it is not price persay, but the equivalence between two commodities as determined by the difference between their magnitude of value?). So if I am understanding this right, he is developing how while the commodity has a dual form, with use-value being the "natural form" i.e. possible outside of a commodity economy as an intrinsic property of utility, its form as a value/exchange-value are what differentiates it as a proper "commodity" in a commodity economy (where production is done for exchange), as a "value-form"?:

“The product of labour is an object of utility in all states of society; but it is only a historically specific epoch of development which presents the labour expended in the production of a useful” (Marx et al., 1981, p. 154) article as an 'objective' property of that article, i.e. as its value. It is only then that the product of labour becomes transformed into a commodity. It therefore follows that the simple form of value of the commodity is at the same time the simple form of value of the product of labour, and also that the development of the commodity-form coincides with the development of the value-form.” (Marx et al., 1981, p. 153-4)

Going back a page, he writes:

“The modern pedlars of free trade, on the other hand, who must get rid of their commodities at any price, stress the quantitative side of the relative form of value. For them, accordingly, there exists neither value, nor magnitude of value, anywhere except in its expression by means of the exchange relation,” (Marx et al., 1981, p. 153)

So what Marx has introduced into the bourgeois understanding of a commodity is that what underlies exchange-value, is value provided by labor and the magnitude of that value by abstract labor-time so that exchange-value is an expression of that underlying value?

Moving forwards again, he writes: "We perceive straight away the insufficiency of the simple form of value: it is an embryonic form which must undergo a series of metamorphoses before it can ripen into the price-form." p.154

I feel like the method Marx is using here is completely backwards from anything else I have read, where he constantly works from the most "embryonic" forms of what he is dealing with, which on its face always seem too simplistic, but then builds on that again and again. In other words, this is breaking my brain lol.