Thanks for providing the link. In context it’s very clear that he is not denying the miracle. He is saying that Jesus started breaking the five loaves and those same five loaves never ran out and fed the multitudes. That’s a miracle and not what Pius was warning against. It’s also not what naturalists argue about people pulling sandwiches from their pockets.
This is the miracle: rather than a multiplication it is a sharing, inspired by faith and prayer. Everyone eats and some is left over: it is the sign of Jesus, the Bread of God for humanity.
St Peter's Square
Sunday, 2 June 2013