On conclusions on the motor actions of the brain and on what is similar to them, such as sleep and wakefulness

As for the conclusions regarding motor actions, their cessation or weakening indicates the presence of a large amount of liquid excess moisture in their tools. Whichever organ it is in, it indicates brain damage. However, damage that is most common to the brain is one that extends to the entire body, such as spinal cord, or to one side of the body, such as paralysis of the limbs and facial paralysis. Sometimes these phenomena, that is, the cessation and weakening of motor actions, occur as a result of warmth or dryness of the brain itself or of some nerve growing from the brain. However, this happens after numerous illnesses and happens little by little as days pass. Damage to any one organ, such as relaxation and the like, sometimes occurs from diseases inherent in this organ, and sometimes from the entry of excess into it from the brain. As for the change in motor actions, if it occurs immediately, this also indicates moisture, and if little by little, then dryness, that is, dryness in the instruments of movement. For example, a change in the movements of the affected person is associated with the brain, that is, a general spasm. It occurs only from humidity, for it occurs immediately, or it occurs with the participation of another organ, as has already been explained; this indicates incomplete blockage. Another example is head shaking. All this indicates the presence of thick matter in the corresponding side of the brain, or indicates weakness or dryness if they appear after previous diseases and develop gradually.

As for what happens in organs more distant from the brain, the same thing should be said about this as we have already said more than once. All these are the essence of movements that go beyond the natural range. We also say that if a person's movements are fast, it means that the nature of his brain is basically hot and dry, and if he is somewhat lazy and sluggish, then his nature is cold and wet. If a person is sick with something and his movements are restless, it means that the nature of his brain is hot; if they are rather quiet, and his strength has not dropped very much, it means that the nature of his brain is cold. Conclusions on sleep and wakefulness also apply to this subject. Know that sleep always depends on a relaxing wet disorder of nature, or on a cold disorder that freezes the movement of the forces of sensation, or follows a strong dissipation of the mental pneuma due to excessive movement, or the directing of forces inward to digest matter; the soul's pneuma rushes out, following them, as it does after eating. If sleep does not come naturally and does not follow fatigue and movement, then it is caused by moisture or congealing of the movements of the sensing force. And if there is no reason for freezing and the signs do not indicate excessive cold - we will mention this later - then the cause of sleep is moisture. However, not all moisture causes sleep, because in old people, despite the moisture in their nature, insomnia lasts a long time. Galen believes that the reason for this lies in the quality of their moisture, which has the properties of bavrak; such moisture causes insomnia because it irritates the brain. But dryness under all circumstances necessarily causes insomnia.