The Moral Arc

What It Is

Michael Shermer's argument that moral progress is real, that it can be measured, and that its engine is the scientific habit of mind. Henry Holt published it in 2015; it runs to around 550 pages, with charts, a long endnote apparatus and a bibliography to match. Shermer founded the Skeptics Society and has written a monthly column for Scientific American for decades. He writes like a debater. You can feel the case being assembled around you.

It is a companion piece to Steven Pinker's The Better Angels of Our Nature, and Pinker has said so himself. Where Pinker documented the decline of violence, Shermer goes after the cause. His answer is reason, abstraction and the widening circle of moral consideration: the same equipment that produced the scientific revolution, turned on human beings.

The title comes from Martin Luther King's line about the arc of the moral universe bending toward justice. Shermer's point is that it does not bend on its own.

Why It Matters

Most people believe some version of this and have never had to defend it. We assume the abolition of slavery, the end of judicial torture, the extension of the franchise and the rest were improvements, and that they were not accidents. Shermer makes you say why, and say it in a form that could in principle turn out to be wrong.

His strongest chapters show moral arguments being won by the same procedures that win scientific ones: by taking an abstraction seriously, by extending a rule you already accept to a case you had been quietly exempting, by refusing to let custom stand in for a reason. That is a genuine claim about the mechanism of moral change, and it is far more interesting than the celebration it is often mistaken for.

Whether it is true is another matter. The causal argument is asserted more than demonstrated — showing that science flourished while slavery was abolished does not establish which pulled which — and Shermer is thin on the religious abolitionists who do not fit the frame. His moral realism, the claim that moral truths sit out there in the world waiting to be discovered, is the position most philosophers reject, and he does not do enough work to earn it. For a book about measurable progress, the near-silence on climate change is conspicuous. Read him as a strong advocate rather than a neutral witness and the book improves, because you start doing the work he skipped.

Before You Read

Long but easy: fifteen hours or so, and the prose never obstructs you. Shermer explains everything, sometimes twice.

Come with a position of your own. This is not a book to be informed by so much as one to test yourself against. Mark the places where you nod without checking. That is where he is doing his work on you.

The closing chapters, which project the arc forward, are the softest thing in the book, and skimming them costs you almost nothing. The historical middle is the argument.

Which Edition to Read

• The Henry Holt paperback (2016) — recommended. The complete text at half the price, carrying the charts and the substantial notes that hold the argument together. One warning, because people fall for it: the paperback carries the subtitle How Science Makes Us Better People, while the hardcover reads How Science and Reason Lead Humanity Toward Truth, Justice, and Freedom. It is the same book. People buy it twice. View on Amazon →
• The Henry Holt hardcover (2015). The first edition, with the charts printed at a size you can actually work with. Worth the money if you intend to interrogate the data rather than take it on trust.
• The ebook. Searchable, and it makes the traffic between text and endnotes painless, which matters in a book that leans this hard on its sources. The cost: this is a chart-heavy argument, and on a phone the charts are useless.

Take the paperback unless the graphs are the reason you came. And keep Pinker's Better Angels within reach; the two books are one argument split across two authors, and Pinker is the one holding the numbers.

Getting the Most From This Book

Read the notes. In a book making an empirical case about history, the endnotes are where the case is either made or exposed, and Shermer's are extensive. Skipping them means taking a professional skeptic's word for it, which he would be the first to tell you not to do.

Argue with the causation as you go. Every time he attributes a moral advance to reason, ask who else was in the room. The answer is frequently a preacher.

And do not read it for reassurance. It is easy to close this book feeling comfortable, and the comfort is the least valuable thing in it.