In answering the question ‘What is Enlightenment?’ Immanuel Kant in 1784 argued that ‘All that is required for this enlightenment is freedom … namely, the freedom of man to make public use of his reason in all matters.’ In the past several years, this commitment to the emancipatory power of reason, and to the further belief that enlightenment is possible if people are willing to attend to the conclusions reached by reason, has been seriously challenged. Examples abound: the rejection of vaccines to protect against the COVID-19 virus, or the refusal of some to acknowledge the legitimacy of the last presidential election in the United States.