Contemporary thinkers and researchers from different parts of the world involved in achieving human development employ Vygotsky's theory in order to deal with new social challenges arising in a global but deeply divided world (Santos, 2000; Souza e Santos, 2008; Martín-Baró, 1998). The chapters of this book shed light onto Vygotsky's initial principles adding critical and social perspectives as a way of expanding his legacy to global contemporary needs such as a critical reflection from the perspective of social change, social dynamics and human development, ethical-political situations of action power, dialectic relationship of the human being with society, contradictions in an individual's dramatic life events and awareness of the social environment to actively change the existing forms of life.