Knowledge has never been so important and at the same time so suspicious. In the era of triumphant rationality, institutionalized science, technological advances and intelligent systems, a strange constellation appears: while science enjoys enormous recognition, many people distrust it, from mere distrust to extreme denial. This rejection is not simply explained by the irrational resistance towards the knowledge of traditional societies; it is telling us something about the type of knowledge generation characteristic of our societies. We will not understand the society in which we live if we do not give an adequate explanation of this strange antagonism. Rationality and its opposite are not at stake, but a certain metamorphosis of the very idea of ??rationality, which can no longer be defined by its simple denial. We would lose a great opportunity to know ourselves if we dismissed this disbelief as a reaction to civilizational progress. We have understood ignorance as if it were the opposite of rationality, but we have barely reflected on the unity of knowledge and ignorance that characterizes us. As always, the advance of knowledge makes us, at the same time, wiser and more ignorant. There is no scientific discovery or technological invention that has not appeared, like its shadow, a new unknown. What we do with the unknown is going to play an increasingly important role in our personal and collective lives.