The best philosophy books that are written as engaging dialogues

This book grabs your attention right from the start. Four people are on a train, and one of them believes in witches. That’s crazy, right? (The witches part, not the train part.) But can you prove that he is wrong? One character trusts science, and only science. Another is a relativist, who believes that each person’s opinion is “true for them.” And then there is the annoying young philosopher, who is just as irritating as she is logical. This is a great book about truth, knowledge, fallibility, and tolerance. Timothy Williamson is one of the best philosophers alive today, and yet this book is accessible and engaging for anyone who wants to think about fundamental questions. The characters are compelling, and the writing is witty and fun.

This might be the best philosophical dialogue ever written, and the subject is nothing less than the meaning of life. The only reason this is not #1 is that it is more challenging to read. But it combines humor and profundity like no other book I know. The grasshopper of the title is the one from Aesop’s fable, who played games all summer, and is now unprepared for winter. The dialogue takes place as winter approaches, and the grasshopper is soon to die. But Bernard Suits is here to defend the grasshopper. After responding to Wittgenstein’s challenge to define the word “game,” the grasshopper argues that playing games is the meaning of life. Right or wrong, this witty, profound meditation will challenge you to think about life’s most important question.

This book singlehandedly revived the dialogue as a genre for contemporary philosophy, and it is now something of a modern classic. As the title indicates, the subject of the dialogue is personal identity and the possibility of life after death. The protagonist, Gretchen Weirob, is terminally ill. Gretchen believes that death will be the end of her existence—that there is no life after death. Her good friend, Sam Miller, disagrees, and he sets out to persuade Gretchen that life after death is possible. They quickly discover that the answer to this question depends on the nature of personal identity. Over the course of three nights, they explore the main theories of personal identity, and the implications of each of them for the possibility of life after death.  

This book is a classic in the philosophy of religion. The great Scottish philosopher, and noted skeptic, David Hume, did not dare publish this book during his lifetime. He gave careful instructions to have it published after his death, and so it was first published in 1779. More than two centuries later, philosophers are still debating the merits of Hume’s arguments. What makes this book so great is that Hume does not straw man his opponents’ arguments. Instead, the characters in Hume’s dialogue state the traditional arguments for the existence of God extremely well. Only then, after they have stated the arguments so well, does Hume’s protagonist, Philo, proceed to attack those arguments with the objections for which he is now legendary.  

The philosopher Alfred North Whitehead once said that all of Western philosophy is a footnote to Plato. That might be an exaggeration, but not by much. One of the greatest features of Plato’s philosophy is that he wrote almost entirely in the form of dialogues. His writings modeled the idea that philosophy is an ongoing conversation between different points of view. They also modeled the idea that philosophy is an exchange of reasons, in pursuit of the truth. Plato wrote many great dialogues, every one of them worth reading, but the Phaedo is my favorite. In this dialogue, Plato comes out of the closet as, well, a Platonist, and whether you agree or disagree, it’s a wild ride.