Here is his Quillette response to critics. Here is one of his arguments, one where I do not find the framing so convincing:
Slaves were always the most desirable spoils of conquest, and anyone who has been to a Passover seder or seen the movie Spartacus knows that slavery was not invented in 18th century Europe or America. Blaming the Enlightenment for slavery is particularly ludicrous given the chronology of abolition…
As the historian Katie Kelaidis put it in The Enlightenment’s Cynical Critics, “Millennia of great moral teachers sought to come to terms with slavery and to mitigate its inhumanity, but no one—not Jesus, not Buddha, not Muhammad, not Socrates—considered the complete liberation of all slaves prior to the Enlightenment. … The Enlightenment was not the inventor of slavery, but it was the inventor of the notion that no one should be held as a slave.”
This strikes me as a classic case of mood affiliation: “we must have a positive mood toward the Enlightenment!” And perhaps we must. But what is wrong with this alternative formulation?:
“Early modern Europe, including its later manifestation of the Enlightenment, brought great benefits to the world. Part of those benefits involved enhanced capacities. Some of those enhanced capacities were used to do great evil, such as to capture, transport, and hold slaves on what was probably an unprecedented scale. The extermination of many indigenous groups could be added to that ledger too. Therefore we should beware of greater capacities, because even when they bring significant good, they also can carry great evils.”
More accurate than Pinker, but it also invokes a more complicated mood toward progress.
I would note also that so many of the most radical abolitionists, including in Britain, were Christians. It is fine to consider them part of the Enlightenment as well, but still to describe the Enlightenment as “the inventor of the notion that no one should be held as a slave” seems off-base to me. The 16th century Spanish Salamancans — theologians I might add — strongly opposed slavery well before the Enlightenment. To call the Salamancans themselves “proto Enlightenment” is perhaps not wrong, but also has a tautological element if such a move is being used to defend the primacy of the Enlightenment (otherwise identified by Pinker as originating in the 18th century) in this regard.
It is also worth a query of the Pinker passage “Blaming the Enlightenment for slavery is particularly ludicrous given the chronology of abolition…” First, you can hold a properly mixed opinion about this whole matter without “blaming the Enlightenment for slavery.” (Most of all I would blame the slave capturers, traders, and owners.) Second, “particularly ludicrous” is too often the mark of an under-argued claim, beware such rhetoric. Third, so many of America’s greatest Enlightenment figures were themselves slaveholders or at least slavery defenders or tolerators. I don’t mean to suggest any simple “blame the Enlightenment” approach here, but surely that is worth a mention and discussion? Finally, the Enlightenment in America is well up and running by 1765, and slavery lasts for a full century more? More yet in Brazil. Maybe that is worth a bit of discussion too?
I am very much an admirer of Pinker and his work, and I consider myself an optimist, especially across longer time frames. But what is sometimes called progress does also have a dark side, and we will do better fighting that dark side if we are clearer — in our own minds and with each other — on how things have run to date.