Nigel Biggar, Regius Professor of Moral and Pastoral Theology at the University of Oxford explains why he believes abortion should be permissible before 18 weeks, but not beyond. Whilst he believes there may always be an element of arbitrariness in choosing a specific date, he defends the development of brain activity, and therefore the beginning of consciousness and the capacity to respond to higher goods, as the key development that makes human beings worthy of special care.