p. 234 - Pinker is discussing knowledge and sociology:
Do better-educated countries get richer, or can richer countries afford more education? One way to cut the knot is to take advantage of the fact that a cause must precede its effect. (emphasis mine)It's clear from earlier in the book that Pinker has no brief for metaphysics as classically conceived. The thing about classical metaphysics is that it is necessary whether you like it or not. The consequence is that metaphysics-haters cannot avoid metaphysics no matter how much they try, and must eventually let metaphysical concepts slip in, consciously or not. A cause must precede its effect is a 100 proof metaphysical concept. And as Pinker's example inadvertently admits, it is more surely known than any scientific conclusions because it is part of the intellectual framework that makes science possible in the first place.
A metaphysical analysis might reflect on a cause must precede its effect and note that it is not precisely articulated. Causes and effects are actually simultaneous. The effect of education is an educated person and it happens at the moment of education. Later on, an educated person may be the cause of riches, so we may loosely talk about education causing riches.
p. 235 - "Better educated girls grow up to have fewer babies, and so are less likely to beget youth bulges with their surfeit of troublemaking young men."
The thrust of Pinker's book is that Enlightenment values and methods have contributed to unprecedented progress over the last few hundred years. And that is certainly true. But, as Chesterton has pointed out, the only way to measure "progress" is to have a stable measure of progress over time. In Chesterton's example, if we decided the world would be better if it was painted green, and we all began to splash green paint everywhere, what would happen if we then decided the world would be better if it were blue? Then all our work painting it green was wasted and we had really made no progress at all.
Up to the time of the Enlightenment (and actually, until very recently) , there was universal agreement that children were a blessing, and indeed among the greatest of blessings. God promised Abraham that his descendants would be as numerous of the stars, and Abraham didn't think it a burden. One of the great achievements of the modern era (one that Pinker emphasizes) is the massive reduction in child mortality over the past 200 years.
And yet, if you had told an Enlightenment philosopher in the year 1770 that one of the great achievements of Western society in the year 2018 would be that many people desired few or no descendants, he'd be puzzled. How is that progress? And if you further told him that mothers would regularly kill their unborn children in order to avoid having a child, he'd be even further puzzled. And he would be positively flabbergasted if you told him the replacement rate of France, Spain and Italy was such that in a few generations Frenchmen, Spaniards and Italians would disappear altogether.
The thing is, the notion of progress is a philosophical one, and those who refuse to reason philosophically end up in places they never dreamed of.