940 science: Greece the notion of a horoscope, in which the positions of the heavenly bodies at the moment of a person’s birth determined that person’s future; thus astronomy was crucial There are surviving Greek horoscopes from the first century b.c.e Astrology quickly became extremely popular, though not everyone was convinced and those who were held many different views as to how it worked Astrology relied on the astronomical and mathematical knowledge of a very small group of experts, and thus made mathematics relevant to the lives of many people in society other than the literate, intellectual elite MECHANICS Mathematics, with an understanding of certain physical principles, was also crucial to the emerging discipline of mechanics From very early times in Greek society there had been craftsmen and engineers who could build a ship, a fountain, or a defensive wall This kind of specialist expertise, which could be written down but was usually passed on in oral and practical lessons from teacher to apprentice, is called a techne, usually translated as “art” or “craft.” The word technology is derived from it Some arts, such as architecture, required mathematical knowledge The physics of motion, materials, and machines was also a topic of interest to some philosophers and other intellectuals Aristotle’s school, the Lyceum, produced a treatise called Mechanical Problems that discussed the workings of common machines such as pulleys and windlasses, not to mention the physics of the knee joint Theories were developed about the behavior of air and liquids under pressure, or pneumatics and hydraulics Pneumatics, hydraulics, and other applications of physics resulted in the production of machines made by a specialized group of intellectual inventors, the mechanists Many of the mechanists’ devices involved steam power Ctesibius of Alexandria, working in the third century b.c.e invented, among other things, a water organ and statues and doors that moved automatically These kinds of toys and spectacular set pieces did not usually have any practical purpose The ancient world had very little industry in the modern sense They were perhaps made to display cleverness and to surprise and entertain a client base, an audience of the social elite, or anyone else who saw the mechanists’ products But there were important practical roles for mechanists as developers of improved military technology, defensive structures, and civic buildings The mechanist Philon of Byzantium, in the second century b.c.e., described how the Greek kings of Egypt, the Ptolemies, funded engineer-mechanists to conduct a series of experiments that would result in building the most effective kind of catapult The lighthouse of Alexandria was also an example of the mechanists’ practical technology Mechanics was heavily utilized by governments and had considerable social importance Many relatively well-off individuals used architects and engineers to construct private buildings and machines for them But the fact that mechan- ics and engineering were largely practical and that practitioners were professionals who got funding and payment—and probably also because manual labor was involved—meant that many of the elite regarded the discipline of mechanics as inferior to mathematics and natural philosophy The ancient Greek intellectual ideal was to study the nature of the universe for the sake of knowledge alone Many mechanists argued against this downgrading of their expertise, and some experts managed to become famous both for their mathematical ability and their useful machines Archimedes (287–212/211 b.c.e.), known for having allegedly shouted “Eureka” (I’ve found it!) in the bath on discovering the law of buoyancy, was well known both as a highly theoretical mathematician and the inventor of many practical machines The Archimedean screw, named after and probably invented by him, made it much easier to lift water from the ground and was widely used for centuries in agriculture During the siege of his city, Syracuse, by the Romans, Archimedes is said to have constructed many innovative war machines, such as a claw that pulled ships out of the water It is unclear how reliable these reports are in their details, but certainly Archimedes was believed to have been important to the defense of Syracuse MEDICINE Traditional healing in Greece consisted of a combination of the use of plants and foodstuffs as drugs, surgical procedures that were traumatic in themselves, and the use of incantations This combined approach to medicine became a techne, an art, though people might also take care of themselves by self-medicating, appealing to the gods and participating in healing cults, or going to experts such as drug collectors (root cutters), purifiers, and magicians In the fi ft h and fourth centuries b.c.e many practitioners of medicine adopted a more exclusively naturalistic approach, which both influenced and was influenced by contemporary developments in philosophy In this naturalistic concept of medicine, physicians developed theories about the nature of the human body as a biological animal and treated illness on the basis of this understanding The texts of the so-called Hippocratic Corpus were written by an unknown number of anonymous authors during this period They were later collected together under the name of the famous physician Hippocrates of Cos (fi ft h century b.c.e.), though it is not known whether Hippocrates actually wrote any of them Some of these Hippocratic texts explicitly assert a naturalistic approach and describe theories of physiology and pathology; others are more practically oriented but assume a naturalistic view The theories described in these works differ, but they often involve one or more substances in the body called humors, such as phlegm, bile, and blood, which need to be in balance for health Physicians demonstrated their authority and expertise by being able to predict the course of a disease and, if it did not seem likely to be fatal, by intervening