When we compromise on justice, we accept or acquiesce to an arrangement that we judge to be unjust, or at least not fully just. Such arrangements are often described as constituting a ‘modus vivendi’. What reasons could we have to accept a modus vivendi, thereby compromising on justice? Given the fact of disagreement on justice, this is an important, but rather neglected question in political philosophy. One possible answer, inspired by John Rawls, is that compromising on justice is only justified if this nonetheless brings us as close to ideal justice as possible under given circumstances. The most straightforward way to take issue with this answer is to present other reasons to compromise on justice. The articles in this book explore epistemic reasons and those that stem from values besides justice, like democracy, peace, toleration and non-subjugation. This book thereby sheds some light on the relevance of compromising for the legitimacy of institutional arrangements. This book was previously published as a special issue of the Critical Review of Social and Political Philosophy.