The debate on the appropriate metric of justice has standardly been conducted with the characteristics and capacities of adults in mind. Recently, this approach has been challenged. This contribution aims to explain this development and to identify the philosophical issues at stake. There are the two major areas of debate. One is the Agency Assumption; standard theories of the metric assume an ideal of responsible agency that may make them inappropriate as a metric for children. The second area of debate revolves around the issue of the intrinsic goods of childhood (see ch. 7). Are there some human goods that are only, or especially, valuable in childhood? Such goods would put the ideal that justice should be neutral with regards to conceptions of the good in question. It is concluded that taking childhood seriously raises new questions regarding neutrality and responsibility for the metric of justice.