The natures are blood...

The natures are blood, bile, wind, and phlegm; The supports are the Aql, its understanding, preservation (from the evil); The pillars are the Noor, the Fire, the Soul, and the Water. The appearance of a man is in (according to) his genes. He could see through light, eat and drink through fire (acid), copulated and moved through the soul, and found the taste of every tasted thing and food through water. This is the basis of man’s characteristics.

A man whose Aql (intelligence) is supported by the Noor becomes knowledgeable, retainer, clever, insightful, and thoughtful. He should also recognise the real situation that he is in, the source of his situation, the reason beyond his existence, and the fate that he will inevitably encounter, through the sincere belief of Allah -azwj s oneness and the submission to the obedience (to Him -azwj ). The soul may move in him, with its heat or coldness.

When heat of the soul influences that man, he will behave in an evil and arrogant manner, feel comfortable, kill, rob, feel pleasant and dashing, commits sins and fornication, and spend lavishly. When the soul covers that man with its coldness, he feels depressed, sad, submissive, withered, and oblivious. These are the symptoms that cause diseases.

This coldness is originated only when the individuals commit a sin and have a drink or food in an hour that is not appropriate to that drink or food-all in the same time; therefore, this will create a certain pain. Imam Jafar-e-Sadiq -asws explained the topic in other words: Man drinks, eats, and works through the fire; hears and smells through the wind; enjoys the taste of food and drink through the water; moves through the soul.

Food and drink cannot be digested in the interior body without the existence of the fire (acid) in the stomach. Without the existence of the wind, the fire of the stomach cannot be flamed (smell, sound, sight and taste all increase the stomach acid secretion) and the dregs cannot find an exit out of the abdomen. Without the existence of the soul, man cannot come and go; i.e., move. Without the existence of the cold water (in the stomach), the fire of the stomach would burn (man).

Without the existence of Noor, man cannot sight or understand. Clay is his nature. The role of bones in the human body is similar to the role of trees on the surface of the earth. The hair on the skin plays the same role as of the grass on the earth. The nerves of the human body play the same role of the bark on trees.