Throughout the human body there are general and particular parts, the general serving to wrap up the particular, and fitting together so snugly that each belongs to the other. This effect is the result of each member in the body having a general sheath, which is so intimately connected with each part that for the purpose of any function or use they act as one. [2] For example, the sheath of any muscle is connected to each of the motor fibres, and forms itself into a coating for them. Similarly the sheath of the liver, pancreas and spleen is connected to the separate parts within them, and the sheath of the lungs, called the pleura, is connected to its inner parts. So too the pericardium is connected to all parts of the heart, and on the general level the peritoneum by means of ligaments is linked with the sheaths of all the viscera. Likewise the membranes of the brain by means of processes drawn out from themselves are connected to all the underlying nodes, and by them to all the fibres, and by them to every part of the body' That is why the head by the action of the two parts of the brain controls all the parts subject to it. These facts are only presented so that from observable objects some idea can be formed how God perceives, sees and knows everything which happens in accordance with order down to the tiniest detail.