Three Scientific Revolutions: How They Transformed Our Conceptions of Reality Read Online Free PDF

portions, the larger discharging its impurities back into the Vena arterials where it is carried to the lungs and breathed out with the remaining purified portion returning to the venous system. This smaller portion slowly flows through tiny vessels passing the septum dividing the two sides of the heart entering drop by drop into the left side. There they mix with the outside pneuma or natural spirit entering the trachea producing a third, higher type of pneuma, the “vital spirit”: the terms ‘vitalism,’ ‘vital principle,’ and Bergson’s élan vitale also were used in the late nineteenth and early twentieth centuries to counter the claim that strictly mechanistic or physiological theories could fully explain evolution. The dark venous blood is then transformed into a bright arterial blood and dispersed via the arteries throughout the body and to the base of the brain where it is activated by another pneuma, an “animal spirit,” animating the body.
    This extraordinary explanation was facilitated by his dissection of the Barbary apes whose anatomy closely resembles humans. It also illustrates the remarkable progress made in devising better investigative methods and more accurate scientific explanations since Aristotle (who located consciousness in the heart). An ardent teleologist, Galen believed that everything was ordained by God, which motivated his research and is one reason his system was so popular during the Middle Ages.
    Brief mention should be made of three other contributors to Alexandrian research. First is Hero or Heron of Alexandria who lived in the first century CE and is known for his ingenious technological inventions in pneumatics and mechanics. These include a globe with attached jets through which the steam from an underlying boiling caldron in successively passing through the jets causes their rotation, a precursor of the steam engine; a cogwheel turned by a twisted screw; multiple pulleys; and a Dioptra for measuring the angles and heights of distant objects.
    Second is Rufus of Ephesus, who also lived in the first century CE and made crucial advances in understanding the structure and functioning of the eyes, some of his nomenclature still used today. Third is Diophantus, who lived in the second century CE and is recognized for his contributions to algebra and for introducing signs for minus, equality, unknowns, and powers used to solve various algebraic functions. While these were important discoveries, progress in algebra remained far behind the advances in geometry made by Euclid and those in trigonometry made by Hipparchus of Nicaea.
    Had these inquiries continued, modern classical science would not have had to wait nearly two millennia before its resumption. Despite the Romans’ extraordinary gifts for engineering and architecture as seen in their splendid aqueducts, temples, baths, and colosseums; for creating some of the world’s greatest literature in the writings of Cicero, Virgil, Horace, Ovid, and Pliny; for their remarkable artistic talents displayed in the lovely frescoes in Livia’s villa and recovered in Pompeii and Etruria; and for their interest in reading resulting in their creating beautifully designed public libraries throughout the empire, one cannot cite a single outstanding mathematician or natural philosopher who was not Greco-Roman.
    After the rise of Christianity and the transfer of the Roman empire by Constantine to Constantinople in 330 CE, the Christian belief that the primary goal in life is gaining salvation and deliverance into heaven replaced attempts to understand and improve the world we live in. If all is ordained by God, gaining God’s help by prayer would be more effective in controlling events than discovering their natural causes as in the saying, “Inshallah” or “God willing.” As Ambrose, one of the Patristic Fathers and Bishop of Milan, declared: “To discuss the nature and position