Defining an oath

I HAD to refer to my Catechism of Catholic Doctrine of Ireland, 1951, to recall what an “oath” was.

“Q 220: What is an oath? An oath is the calling of God to witness that what we say is true, or that we will do what we promise.

“Q 221: When is an oath lawful? For an oath to be lawful we must have sufficient reason for taking it, and we must say only what was true, or promise only what is lawful.” Of course a child who had made his Confirmation would have memorised and understood this, wouldn’t he?