We live in a context of high and rising inequality. Average real wages stagnate while the pay of top earners continues to grow. Welfare benefits and tax credits are hit by repeated rounds of cuts while attempts to control bankers bonuses prove futile. As Sally Witcher puts it in this wide-ranging and ambitious book, the social fabric is being stretched so far that it may finally be ripped asunder.

Against this backdrop, Witcher sets out a vision for an inclusive and socially just society. It is a society in which diversity – ‘of people, cultures, forms of contribution’ (p. 205) – is recognised and valued, and where the goal of social cohesion is balanced against the need to treat people as individuals. It is sensitive to diverse characteristics while not being over sensitive: neither ‘difference-blind’ nor ‘sameness-blind’ (p. 53).

In developing her theory, Witcher takes us on a grand tour of the literature on social justice, poverty, discrimination and exclusion, dedicating a chapter to each concept. Each of these chapters is a veritable parade of theories and theorists, from Rousseau and Marx to Nozick, Rawls and Sen, right up to contemporary analysis by Burchardt and Vizard, Dean, Lister and Levitas. In her own words, Witcher has ‘roamed across topics and disciplines’ (p. vii), ‘knitting together themes’ (p. 205) and picking ‘helpful tidbits from the discourse smorgasbord’ (p. 128), in an attempt to build a big picture which does not risk slipping down into the gaps between disciplines.

The ultimate vision is rooted in Walzer's (Reference Walzer1983) concept of ‘complex equality’, in which the distribution of goods in one sphere (e.g. income) is unable to dominate the distribution of goods in other spheres (e.g. education, health care, political power). In Witcher's words, there must be ‘separation yet coherence’ between economic, social, political and civil systems. On to this central structure she builds two key preoccupations. The first is a focus on the significance of barriers other than those driven by traditional resource constraints, including access issues and discriminatory practices and attitudes. A higher income (or a Ph.D.) is not sufficient to ensure the inclusion of the person in a wheelchair outside a building accessed only by stairs, or the black job candidate facing a racist employer. The second is the importance of human relationships and human engagement: people need to feel respected, included and equally valued, not only to be so. Part of what is terrible about poverty is the associated stigma and challenge to self-respect, not just poorer outcomes or objective injustices (such as the inability to access goods in other spheres). In Witcher's view, social exclusion can only be addressed by a dual focus on both structural issues and the feelings and motivations of individuals.

Underlying all this is a commitment to the recognition of diversity and the ‘equal valuing of difference’ (p. 208), although Witcher is candid about the tension between inclusion and difference, and the difficulty of ensuring social cohesion while promoting the expression of diversity. Her concern with the social fabric is not only that it may rip as it stretches vertically, but also about its horizontal reach. How far does inclusion prevent people being different, and how far does recognising difference challenge a cohesive society? ‘If a policy of singling out a group for special (different) treatment is de facto exclusive, the challenge becomes how to avoid ‘including by excluding’ people with aspirations, needs, cultural norms . . . which differ from the majority’ (p. 211).

Her solution is that instead of separating people into one-dimensional social categories, we need to acknowledge their multiple characteristics, circumstances and identities: ‘inclusion can be achieved through the existence of multiple points of commonality and mutually enriching difference’. As a result, she thinks strengthening peer groups and supporting the development of new connections with different networks might be useful goals for social policy.

This is a highly intellectual book – a rewarding read but by no means an easy one. The vision it offers is largely abstract and unapologetically theoretical, and though in the penultimate chapter Witcher attempts to explore the implications for the design and delivery of key social services and benefits, she offers not a list of answers but rather a list of challenges and issues for policymakers and academics to think about. In her own words, the book offers ‘a broad-brush outline on a wide canvas’, and she challenges others to move in closer, explore the landscape and fill in the detail. In particular, she emphasises the need to draw in the voices of those ‘on the sharp end’, those not usually heard in public debate.

Of course, the challenge of moving from here to there is (even) bigger than that of filling in the detail. Witcher points unequivocally to ‘the blatantly dysfunctional form of capitalism we currently endure’ as the source of both the unequal concentration of power and resources and the barriers to inclusion these create. As she also points out, the most significant limitation to inclusive equality are the ‘people whose “difference” is that they do not want equality’. Witcher's main focus in this particular passage is on ‘cultures characterized by the belief that some groups are innately inferior to others’ but the charge surely applies also to those who monopolise wealth and power out of self-interest rather than cultural belief. My sense is that this book is insufficiently accessible to start the revolution on its own; but it would be a positive and welcome step if its central vision and key messages filter into public debate.