The modern world is in crisis: at the factual level, with various challenges that tend to interact and reinforce each other; and at the epistemic level, where no single science or expertise alone can grasp the complexity of what is going on. In this publication, such basic epistemic challenges are addressed, critically and constructively; in this perspective, four current cases are discussed and assessed, such as the United Nations Agenda 2030 for sustainable development. On this background, some proposals for epistemic and institutional improvements are considered.