“When the court is considering whether a particular child should be called as a witness, the court will have to weigh two considerations: the advantages that will bring to the determination of the truth and the damage it may do to the welfare of this or any other child. A fair trial is a trial which is fair in the light of the issues which have to be decided. Mr Geekie accepts that the welfare of the child is also a relevant consideration, albeit not the paramount consideration in this respect. He is right to do so, because the object of the proceedings is to promote the welfare of this and other children. The hearing cannot be fair to them unless their interests are given great weight.”