Book excerpt: This book presents a series of analyses of educational policies – largely in the UK, but some also in Europe – researched by a team of social scientists who share a commitment to social justice and equity in education. We explore what social justice means, in educational policy and practice, and how it impacts on our understanding of both ‘educational science’ and ‘the public good’. Using a social constructivist approach, the book argues that social justice requires a particular and critical analysis of the meaning of meritocracy, and of the way this term turns educational policies towards treating learning as a competition, in which many young people are constructed as ‘losers’. We discuss how many terms in education are essentialised and have specific, and different, meanings for particular social groups, and how this may create issues in both quantitative survey methods and in determining what is ‘the public good’. We discuss social justice across a range of intersecting social characteristics, including social class, ethnicity and gender, as they are applied across the educational policy spectrum, from early years to postgraduate education. We examine the ways that young people construct their identities, and the implications of this for understanding the ‘public good’ in educational practice. We consider the responsibilities of educational researchers to acknowledge these issues, and offer examples of researching with such a commitment. We conclude by considering how educational policy might contribute to a socially just, equitable and inclusive public good.