Introduction

The world is full of disagreements.

We argue about race, abortion, speech, gender, religion, taxes, and politics. We argue at family dinners, on social media, in classrooms, and in legislatures. We argue because we think these things matter. They shape our lives, our laws, and even our understanding of what it means to be human.

Yet something about these debates is peculiar.

Most of us are intelligent, informed, and sincere. Some of us even have a sense of humor.

But the arguments, it seems, rarely stem from the surface issues. The debate over abortion, for example, isn’t just about an unborn child or a woman’s right to choose. The debate about free speech isn’t just about words. The debate about taxing the rich isn’t just about money.

Yes, the surface-level disagreements are what cause the friction, but it’s the deeper-level disagreements—stemming from mostly unexamined assumptions about reality, knowledge, morality, and value—that are at the crux of the issue.

What kind of world do we inhabit? How can we know what is true? What makes something right or wrong? What should we value? Humans have been trying to answer these kinds of questions for thousands of years. In order to answer the practical questions, we must first wrestle with the foundational ones—or at least be aware of them.

This book is an attempt to do exactly that.

It is not a manifesto. It is not a political program. It is not a collection of talking points for one side or the other. Its purpose is not to tell you what to think, but to examine how we think and how our assumptions shape the conclusions we reach.

In the first part of the book, we explore the structure of the world itself. We begin with some of philosophy’s oldest questions: What is real? How do we know? What is value? These questions may sound abstruse,¹ [like that word!], but they influence every belief we hold, and they’re actually fun to talk about.

In the second part, we play with ideas. We examine controversial topics not because they are easy, but because they are difficult, interesting, and more fun to play with. The goal is not necessarily to settle the arguments, but to understand them. We explore competing perspectives, hidden assumptions, and some of the trade-offs hiding beneath our everyday, lazy thinking.

In the final part, we step back and consider the broader implications. What are the costs of free speech? What kind of society should we strive to create? How should free individuals live together when they disagree about fundamental things?

The world is complicated. Human beings are fallible. Our knowledge is limited. But none of that relieves us of the responsibility to think carefully—to think harder.

The goal of this book is not certainty. The goal is to make it easier for you to understand why you believe what you believe, and to consider why someone else might think differently.

That seems like a good place to start.