From the Guardian:
We believe in sexual freedom. We take it for granted that consenting men and women have the right to do what they like with their bodies. Sex is everywhere in our culture. We love to think and talk about it; we devour news about celebrities' affairs; we produce and consume pornography on an unprecedented scale. We think it wrong that in other cultures its discussion is censured, people suffer for their sexual orientation, women are treated as second-class citizens, or adulterers are put to death.
Yet a few centuries ago, our own society was like this too. In the 1600s people were still being executed for adultery in England, Scotland and north America, and across Europe. Everywhere in the west, sex outside marriage was illegal, and the church, the state and ordinary people devoted huge efforts to hunting it down and punishing it. This was a central feature of Christian society, one that had grown steadily in importance since late antiquity. So how and when did our culture change so strikingly? Where does our current outlook come from? The answers lie in one of the great untold stories about the creation of our modern condition.