Around 600 BC, Thales of Miletus set out to discover the causes
of earthquakes. It had previously been imagined that they were
caused by Poseidon, the sea god, but Thales proposed that
earthquakes resulted from tremors in the water. His theory was
wrong, but his method was revolutionary: he was among the first
thinkers to try to understand the natural world without
reference to the supernatural. Thanks to this fundamental shift
in outlook, Thales and his fellow Greeks are widely acknowledged
as the first scientists. Classicist and anthropologist G. E. R.
Lloyd’s history traces the development of science in ancient
Greece from the earliest theories of Thales and his fellow
Milesians to Ptolemy and Galen in the 2nd century AD. He
identifies the key figures and their remarkable contributions to
the sum of human knowledge. Pythagoras and his followers were
the first to give the study of nature a mathematical foundation;
the Hippocratic authors were the first to identify illness as a
natural phenomenon, not caused