How are we to live together in a diverse society? In a time of polarization, fragmentation, and inequality, the liberal answer to this question requires a new defense. Democratic institutions are under threat. Identity groups seeking recognition often encounter resistance. In response, The Structure of the Open Society defends the significance of institutions that foster freedom, equality, and autonomy. And he argues that this age of identity calls for an inclusive and open mentality.Famously, Karl Popper identified holism as the enemy of the open society. It leads to tribal communities with credulous and close-minded members. But the holist ontology defended here reveals how irreducibly social structures can support the basic rights that lie at the heart of liberal democracy. Crucially, they need not impair, but can in fact enhance critical reflection, toleration and epistemic modesty, which are vital for the resilience of a liberal democracy. To defend these ideals, Hindriks proposes that a society is a cluster of social structures. Their two building blocks are equilibria, which reflect the incentives people have, and rules, which give meaning to and govern their actions. In principle, social structures enable them to interact in mutually beneficial ways. Yet, they also constrain their behavior. To secure basic rights, an appropriate mix of constraints and enablements must be supported by a culture that recognizes their significance for a sustainable society.