He said, therefore, we can't deal with consumers, we can't deal with non-reproducible goods, we have to deal with reproducible goods.
And since we can't talk about consumers, value must come from something inherent in the object, namely, labor hours.
Another reason to use labor hours is that he and Ricardo were trying to measure value all the time.
Because science meant measurement, even in those days, for these people.
And so therefore, how do you measure value and how do you measure changes?
Looking for some hard quantity and it concluded labor hours was about the best thing they could get to.
So that was one big fallacy, one big dominant fallacy in economic thought.