One of the actions which signifies the presence of a Catholic Christian is making the sign of the cross. The result would startle us if we counted up the number of times we make it during one day or during one celebration of Holy Mass. This sign becomes an automatic part of our lives, to sign the sign of the cross can be almost a reflex action; and surely non-Catholics may be forgiven if they suppose it to be just another bit of external ritual, enforced habit or even superstition. Perhaps at any one moment it may in the concrete be only one of these things, but this sign has an almost infinite richness in itself ot which it may be worth while to attempt a brief exploration.