Marta Harnecker A World to Build: New Paths toward Twenty-First Century Socialism, New York: Monthly Review Press, 2015; 224 pp: ISBN: 9781583674673, 18.20 [pounds sterling] (pbk). Marta Harnecker's A World to Build aims to serve as a tool for the praxis of social and political activists of 21st century Latin America. In particular, it is aimed at those who fight neoliberalism and oppose it with a socialist and radically democratic project (Mouffe & Laclau 2001). The book is written in a way that is based on the experience of struggle and the efforts of those seeking social change, and by different left-wing (or progressive) governments and social movements, using a Marxist economic-political theoretical framework. The author provides an overview of the Latin American progressive context. This includes the propitious correlation of forces that (at least until 2015) existed in the continent for the movements of socialist change. This is followed by a characterisation of the '21st century socialism' which these movements sought to build and, with it, the difficulties and challenges that appear in the path of the new 'political tool' that should help to impulse the changes. All this, we should say, is part of an implicit discussion with social movements and the autonomist thesis that informs many of them (Holloway 2005). The book includes a constant productive dialogue between the social-political context of Latin America, and diverse theories and political alternatives, always proposing orientations to the forces of social change that oppose neoliberalism in the continent. It's in this context that the title of the book defiantly emerges and forces the question 'What world to build'? Citing political leaders such as Chavez (2007) and academics such as Moulian (2000), the author answers, 'a socialist world'. But, she continues, instead of the old bureaucratic socialism, a new one of popular leadership that really aims to accomplish the socialisation of the means of production and the organisation of them in the control of workers who participate in the production. A socialism that allows us to reach a more total form of human development, in which the person is understood as a social being, thereby transcending the division between intellectual and manual work. This socialism, Harnecker says, should take Marx and Engels but should also go beyond them, rescuing for example new elaborations such as the ones of Lebowitz (2008). In sum, we should seek a democratic socialism in which popular power plays a central role, aiming to consolidate an auto-government of the people, where political parties and governments seek only to orientate social processes, using the potentials of participatory --not bourgeois--and delegate democracy, where power is spread, where bureaucratic vices and corruption are fought: an ecologist and feminist socialism. How is this world possible? Harnecker's book provides ample empirical evidence to show the propitious correlation of forces that socialist alternatives faced from the end of 20th century until the beginning of the present one, both inside and outside Latin America. The first signs of this, the author argues, come with the social mobilisations to resist neoliberalism in the 1990s. A second wave can be seen in the political consolidations that these movements reach with diverse strength, where victories like the ones of Chavez in Venezuela (1998), Morales in Bolivia (2006) and Correa in Ecuador (2007) stand out. With this and other advances of popular forces, the author argues that the continent is facing a stage of'transition to socialism'. Kirchner's governments in Argentina (2003-2015) and the ones of Lula and Roussef (2003-2016) in Brazil are also named as 'advances', but Harnecker doesn't explore much about them. Although she considers them 'left wing governments', she doesn't group them into the ones that will contribute to the construction of 21 st century socialism, nor does she name their reforms as ones that can help the state to construct popular power (Urrutia & Seguel 2013). …