Ibn al-Nafis
A physician who was the first to accurately describe the pulmonary circulation of blood, challenging Galen's long-held theories.
Quotes by Ibn al-Nafis
The blood, after it has been refined in the right ventricle, must be propelled to the left ventricle where the vital spirit is formed. But there is no passageway between these two ventricles. The heart is a solid organ and has no pores, as Galen imagined. The blood must therefore pass from the right ventricle to the left ventricle by way of the pulmonary artery and then through the lungs, where it is mixed with air, and then through the pulmonary vein to the left ventricle.
The heart has only two ventricles, not three as Galen claimed. The septum between the two ventricles is solid and has no visible or invisible pores.
Galen's assertion that the blood passes directly from the right ventricle to the left ventricle through invisible pores in the septum is incorrect. This is a fundamental error in his understanding of the circulatory system.
The lungs are not merely for cooling the blood, but are essential for its aeration and for the formation of the vital spirit.
The vital spirit is not formed in the liver, as some ancient physicians believed, but in the left ventricle of the heart, through the mixing of blood and air in the lungs.
The brain is the seat of sensation and voluntary movement, and not the heart, as some philosophers have erroneously believed.
The pulse is not solely a movement of the arteries, but a movement of the heart that is transmitted to the arteries.
The liver's function is to produce blood, but it does not play a direct role in the formation of the vital spirit.
Dissection of human bodies is permissible and even necessary for understanding the true structure and function of the human body, contrary to some religious prohibitions.
The writings of ancient authorities, even Galen, should not be accepted blindly, but must be critically examined and verified through observation and reason.
The pulmonary artery carries blood, not air, from the right ventricle to the lungs.
The pulmonary vein carries blood, mixed with air, from the lungs to the left ventricle.
The purpose of the lungs is not only to cool the heart, but also to prepare the blood for the formation of the vital spirit.
The arteries contain blood, not air, as some ancient physicians believed.
The veins carry blood to the heart, while the arteries carry blood away from the heart.
The brain is the primary organ of the nervous system and the source of all sensation and movement.
The human body is a complex and interconnected system, and understanding one part requires understanding its relationship to the whole.
The physician must rely on observation and experience, in addition to the knowledge inherited from previous generations.
The human body is created in the most perfect form, and every organ has a specific and essential function.
The heart is the engine of the body, driving the circulation of blood throughout the system.