One of the most succinct and comprehensive overviews of Marx I've read. Includes a biography, an overview of prior forms of utopian socialism and liberal economic theory, fucking Hegel, the labour theory of consciousness and value (by transforming the land we add value to it, and furthermore transform and add value to ourselves), the falling rate of profit and economic crises (if profit is derived from labour, then the replacement of laborers by machines, out of competition with other corporations, will lead to less and less valuable commodities, until the market crashes), the reserve army of labour (while there is a pool of unemployed workers, capitalists can hire them at low wages because they're desperate), proletariat/class consciousness (through collective labour we realise our essential power to capital and therefore our subversive power as a class) and international socialism (only world revolution can dismantle the hegemony of the market/there can be no socialism in one country).
Misses or fails to develop a few key ideas such as primitive accumulation (colonial land theft/the dispossession of indigenous peoples from subsistence living), the bourgeois family (patriarchy and property inheritance), commodity fetishism (the veiling of the sphere of production in the sphere of exchange, which generates a mystical allure to commodities) and fictitious capital (speculation and debt). Doesn't dive into the many developments on Marx since the 20th century (Gramsci, Luxembourg, Mao, Fanon, Althusser, Foucault, Delueze & Guattari, Shiva & Mies, Bookchin, Harvey, Federici, Laclau & Mouffe, Zizek, Haraway, Graeber); but that would take an entire other book (and it isn't the point of this book), so it's no fault of Callinocos. A bigger issue is his failure to mention and address critiques from other sections of the left such as anarchism (what if the state never withers away + there are more hierarchies than class), feminism (patriarchy pre-exists capitalist class relations + care and maintenance pre-exists production as valuable labour), black liberation (I actually can't think of anything right now, lol soz).
Some may question Marx's relevance to 21st century capital; but it's not that Marx is (now) wrong, it's more that we have to historically situate him in a time of rapid industrialisation, where great numbers of rural families were forced into the mass anonymity of city existence; and whose identities were subsequently reshaped by factory labour and capitalist economic relations. We still live under capitalism, but we can't understand the gig economy through the spatiotemporality of the factory floor. However, while the structure of work has changed, its economic relation of exploitation has not. You either sell your body as a labourer to gain a wage, or you manage a body of laborers to gain profit. Callinocos is right when he says it's not the type of work you do that matters, but your relation in the mode of production. This, fundamentally, hasn't changed since Marx's time, and it's why Marx still matters.