Melinda Gates, who identified herself as a practicing Catholic, believes that people should be able to decide if and when to have babies, and that they should be able to use any available birth control device to avoid becoming pregnant. She stresses that birth control should not be controversial, but it often is. She stresses that the focus of her talk is birth control, not abortion, but that the two terms have become confused these days.

Gates was speaking on behalf of the Gates Foundation, announcing its new project: to help the 200 million women of the world who want access to birth control but who don’t have access.

The topic of Gates’ talk makes perfect sense to me, but she is up against some deep-seated suspicion that is inter-twined with religion, tradition and path dependence. In America, where 98% of women use birth control, a vocal and powerful minority of people nonetheless believe that all use of birth control is immoral. Many people have become intimidated by the accusations made by religious conservatives and have become reluctant to speak up for the universal right to birth control.

Gates points out that the nuns who taught her in high school encouraged her to “question received teachings,” and that she is doing exactly that. She urges that sex is sacred, even for most of the people using birth control, and it is a way to take better care for the children one already has by proactively planning one’s family.

Gates argues that making birth control widely available where it currently isn’t (Sub-Saharan Africa, South Asia and Afghanistan) would be transformative. The numbers back her up. She has spoken to women in many parts of the world, and they tell her that they want to actively plan their families. In the biggest province of India, only 29% of women use birth control of any type. In Nigeria, the number is only 10%. In Senagal, 12% and in Chad it is merely 2%.

Gates talk is a personal, non-confrontational one. But it is also a talk that presents a big challenge: We need to have this conversation, and that we need to make birth control an essential part of every public health agenda.