 We can speak either of ‘a’ child or, more generally, of ‘children’. There is a difference between considering how in some matter the child most directly concerned is affected and considering how any policy or action in respect of that one child may also have consequences for other children. Indeed we might consider how any policy or action at all has implications—even if very indirect and attenuated—for all children. However, it is plausible to construe a use of ‘children’ within a formulation of the BIP as requiring us to attend to the impact of a policy, practice, or activity upon those young persons most obviously and directly affected. The BIP’s origins are to be found in custody disputes where the law had to make a determination in respect of a couple’s children. Even if there were several children the court had to decide in respect of each individual child what was the most appropriate course of action. The provenance of the BIP shows itself in the continued use of the singular term ‘child’.