336. Moreover, the methods by which the Divine Providence operates upon the means and through these to form man and to perfect him are also infinite in number and variety. They are as numerous as the operations of the Divine Wisdom from the Divine Love to save man, and thus as numerous as the operations of the Divine Providence in accordance with its laws which have been previously treated of. That these methods are of a very hidden nature was illustrated above by the operations of the soul upon the body, about which man knows so little that it scarcely amounts to anything; as how the eye, the ear, the nose, the tongue and the skin function; how the stomach digests, the mesentery prepares the chyle and the liver the blood; how the pancreas and the spleen purify the blood, the kidneys separate it from impure humours, the heart collects and distributes it and the lungs purify it and pass it on; and how the brain refines the blood and vivifies it anew; besides innumerable other things which are all hidden into which scarcely any knowledge can enter. From this it is clear that still less can the hidden operations of the Divine Providence be entered into; it is enough that its laws are known.