Why Political Philosophy Should Be Robust

Political philosophers and theorists make arguments about high-stakes problems. This article shows that those theories would be more credible if political philosophers ensured their work was robust: capable of withstanding reasonable changes to their assumptions and to the cases to which their arguments apply. The world is varied and inconstant. As a result, scientists and social scientists recognize the virtue of robustness. This article shows why political philosophers should also do so. It defines robustness, demonstrates its value, and shows how it can be evaluated. Illustrating the stakes of robustness, the article assesses prominent arguments concerning multiculturalism and open borders. Avoiding misunderstanding and confusion should be a central aim of political philosophy. To sidestep these outcomes and to reassure scholars that one's theory is not subject to concerns about its credibility, it will often be reasonable for philosophers to explicitly test their theories for robustness.