Sacramental signs do not make present the realities which they signify by spatially enclosing them, in the way in which a gas-cylinder may contain hydrogen, or by being instruments by which they are manufactured, as a sausage machine produces sausages, or by being channels through which they are communicated, as a water-pipe delivers water, but by being divinely-ordained efficacious signs of them.
E.L. Mascall
