Subsection 2. Divisions of the body, humours and spirits.

There are many ways of dividing the parts of the body. The most widely accepted is Laurentius’s, taken from Hippocrates: into what the body contains and the parts that contain it. What it contains consists of humours or spirits.

A humour is a liquid or flowing part of the body, contained within it for its preservation. It is either innate, present from birth, or acquired. The radical, or innate, humour is replenished daily by nourishment, which some call cambium; they hold that the secondary humours ros and gluten sustain it. Acquired humour sustains the four primary humours, which arise from the first digestive processing in the liver, by which chyle is separated out.

Some divide humours into useful fluids and waste products. But Crato, following Hippocrates, considers all four to be juices rather than waste, indispensable to the life of every creature. Although all four are included in the mass of blood, each has distinct properties by which it is distinguished from the others, and from the acquired, faulty or diseased humours, as Melanchthon calls them.

Blood is a hot, sweet, temperate, red humour, prepared in the mesenteric veins and made in the liver from the most temperate parts of the chyle. Its function is to nourish the whole body and give it strength and colour, being distributed through every part by the veins. From it, spirits are first generated in the heart and then conveyed through the arteries to the other parts.

Pituita, or phlegm, is a cold, moist humour generated in the liver from the colder part of the chyle—the white juice derived from food digested in the stomach. Its function is to nourish and moisten the moving parts of the body, such as the tongue, so that they do not become too dry.

Choler is hot, dry and bitter, generated from the hotter parts of the chyle and collected in the gallbladder. It assists the body’s natural heat and senses, and helps expel waste.

Melancholy is cold and dry, thick, black and sour, generated from the more sedimentary part of nourishment and purged from the spleen. It restrains the two hot humours, blood and choler, preserving them within the blood and nourishing the bones. These four humours have certain correspondences with the four elements and the four ages of human life.

To these humours you may add serum, the substance from which urine is made, and sweat and tears, the waste humours produced by the third stage of digestive processing.

Spirit is an extremely fine vapour extracted from the blood, the soul’s instrument for carrying out all its actions. Some consider it a shared link or medium between body and soul; Paracelsus considers it a fourth soul in its own right. Melanchthon holds that these spirits originate in the heart: generated there and then conveyed to the brain, they acquire a different nature.

There are three kinds of spirit, corresponding to the three principal organs—the brain, heart and liver: natural, vital and animal. Natural spirits are generated in the liver and distributed through the veins to carry out the natural functions. Vital spirits are made in the heart from the natural spirits and conveyed through the arteries to all the other parts. If these spirits cease, life ceases, as in syncope or fainting. Animal spirits, formed from the vital spirits, are carried up to the brain and distributed through the nerves to the parts under its control, giving sensation and movement to them all.