How we cite our quotes: (Chapter.Section.Paragraph) or (Chapter.Paragraph)
Quote #7
The capitalist maintains his rights as a purchaser when he tries to make the working day as long as possible, and, where possible, to make two working days out of one. On the other hand, the peculiar nature of the commodity sold implies a limit to its consumption by the purchaser, and the worker maintains his right as a seller when he wishes to reduce the working day to a particular normal length. There is here therefore an antinomy, of right against right, both equally bearing the seal of the law of exchange. Between equal rights, force decides. Hence, in the history of capitalist production, the establishment of a norm for the working day presents itself a a struggle over the limits of that day, a struggle between collective capital, i.e. the class of capitalists, and collective labour, i.e. the working class. (10.1.8)
The buying and selling of labor-power (not to mention the exploitation of it) is what makes capitalism tick, and it's all legal. Workers have the right to sell their labor-power, and capitalists have their right to buy it. Their rights are equal—so rights don't decide who gets a leg up on someone else. Rather, force decides: the stronger side gets to call the shots on the length of the working day, for example. When workers go on strike—when they simply refuse to work—they might win better conditions.
Quote #8
Capital therefore takes no account of the health and the length of life of the worker, unless society forces it to do so. Its answer to the outcry about the physical and mental degradation, the premature death, the torture of over-work, is this: Should that pain trouble us, since it increases our pleasure (profit)? But looking at these things as a whole, it is evident that this does not depend on the will, either good or bad, of the individual capitalist. Under free competition, the immanent laws of capitalist production confront the individual capitalist as a coercive force external to him. (10.5.8)
Thinkers such as Adam Smith had argued before Marx that each individual pursuing his or her own advantage/pleasure/profit would result in a just system. But Marx says that capitalists don't care about the well-being of workers (they only rarely recognize that it's in their own interest to have happier employees) and will just seek their own self-interest to the max—and this will create injustice.
Quote #9
For 'protection' against the serpent of their agonies, the workers have to put their heads together and, as a class, compel the passing of a law, an all-powerful social barrier by which they can be prevented from selling themselves and their families into slavery and death by voluntary contract with capital. (10.7.7)
Marx is best known as a revolutionary calling for the overthrow of capitalist governments, but he also advocated for reform measures, as here.