More specifically, this book will try to establish the following points. First, there are not two great liberal social and political systems but three. One is democracy—political liberalism—by which we decide who is entitled to use force; another is capitalism—economic liberalism—by which we decide how to allocate resources. The third is liberal science, by which we decide who is right. Second, the third system has been astoundingly successful, not merely as a producer of technology but also, far more important, as a peacemaker and builder of social bridges. Its great advantages as a social system for raising and settling differences of opinion are inherent, not incidental. However, its disadvantages—it causes pain and suffering, it creates legions of losers and outsiders, it is disorienting and unsettling, it allows and even thrives on prejudice and bias—are also inherent. And today it is once again under attack. Third, the attackers seek to undermine the two social rules which make liberal science possible. (I’ll outline them in the next chapter and elaborate them in the rest of the book.) For the system to function, people must try to follow those rules even if they would prefer not to. Unfortunately, many people are forgetting them, ignoring them, or carving out exemptions. That trend must be fought, because, fourth, the alternatives to liberal science lead straight to authoritarianism. And intellectual authoritarianism, although once the province of the religious and the political right in America, is now flourishing among the secular and the political left. Fifth, behind the new authoritarian push are three idealistic impulses: Fundamentalists want to protect the truth. Egalitarians want to help the oppressed and let in the excluded. Humanitarians want to stop verbal violence and the pain it causes. The three impulses are now working in concert. Sixth, fundamentalism, properly understood, is not about religion. It is about the inability to seriously entertain the possibility that one might be wrong. In individuals such fundamentalism is natural and, within reason, desirable. But when it becomes the foundation for an intellectual system, it is inherently a threat to freedom of thought. Seventh, there is no way to advance knowledge peacefully and productively by adhering to the principles advocated by egalitarians and humanitarians. Their principles are poisonous to liberal science and ultimately to peace and freedom. Eighth, no social principle in the world is more foolish and dangerous than the rapidly rising notion that hurtful words and ideas are a form of violence or torture (e.g., “harassment”) and that their perpetrators should be treated accordingly. That notion leads to the criminalization of criticism and the empowerment of authorities to regulate it. The new sensitivity is the old authoritarianism in disguise, and it is just as noxious.