If you’ve watched 19 Kids and Counting or any of the related Duggar family specials on the Discovery Health channel, you might be vaguely aware of the Quiverfull movement, even if you don’t know its name. Though the Duggars play coy in the press about whether they’re actually associated with the movement, they’ve been featured speakers and guests at Quiverfull events in the past.

So what is Quiverfull? It’s a conservative evangelical Christian movement to have as many babies as possible. Inspired by a Bible verse about G-d filling the quivers of the righteous with as many arrows as possible, this Christian subsect believes that the best way to control governments and change society is by strength in numbers. And this means having as many children as possible. Kathryn Joyce’s thorough and well-researched book Quiverfull: Inside the Christian Patriarchy Movement does a spectacular job of explaining the roots of the movement as well as identifying key players, all without judgment. She answers the fundamental question of how women justify going along with Quiverfull and spending most of their reproductive years pumping out kids. And, as the title of the book notes, Quiverfull isn’t only about children – it’s about the rest of the movement’s ideals, including women not working outside the home, remaining celibate until marriage, and being subservient to their husbands. It’s the last part that made it hard for me, as a feminist, to read this book – all the workshops and lectures devoted to helping women learn how to be perfect servants and let their husbands be the leaders of the family made me feel queasy. That said, the queasiness is exactly what makes this book so eminently readable – it’s important to understand the intellectual roots of this movement in order to understand what makes people embrace it. You won’t be able to put Quiverfull down, but you might also not be able to sleep.