A serious engagement with enlightenment thought could lead you to understanding why liberal radicalism failed on its own terms and why Marx was necessary in history. Pinker is more interested in defending modern capitalism, which would have made Adam Smith shoot himself in the head. Capitalism today is not what any of those guys like Smith or Rousseau wanted. Marx takes up their project, pulls out the contradictions in them, and goes beyond them.
A serious engagement with enlightenment thought could lead you to understanding why liberal radicalism failed on its own terms and why Marx was necessary in history. Pinker is more interested in defending modern capitalism, which would have made Adam Smith shoot himself in the head. Capitalism today is not what any of those guys like Smith or Rousseau wanted. Marx takes up their project, pulls out the contradictions in them, and goes beyond them.