To be invited to deliver the first John J. Billings Memorial Lecture is a great honour. Two years ago, I felt humbled and privileged to be the homilist at Dr John’s funeral Mass in St Patrick’s Cathedral Melbourne. As on that occasion, we remember and celebrate a great man, a wise leader with a generous heart and gentle patience. In developing the most widely-known method of natural fertility awareness, this courageous man worked with Dr. Lyn Billings, his beloved wife who is with us tonight. Undaunted by challenges they have been able to help thousands of couples around the world by offering a reliable and ethical way of understanding and regulating human fertility. You are all part of that great continuing project initiated by Dr John and Dr Lyn Billings. I thank you for your dedication, your sacrifices and commitment.