Philosophical Society of Washington

The Extraterrestrial Life Debate: Historical, Philosophical and Scientific Perspectives

Steven Dick,
U.S. Naval Observatory

2120th Meeting Abstract
Friday, October 6, 2000 at 8:15 p.m.


Extraterrestrial life has been one of the major themes of 20th century science, and has roots that go back to ancient Greece. Because the debate has been at the very limits of science, it is a window on how science has functioned with little data, attempting to answer a question of profound importance to humanity's place in the universe. Today the discovery of the Martian meteorite, life in extreme environments, a likely ocean on Europa, and some 50 planets beyond our Sun assures that the search will intensify in the 21st century.

In this lecture, I will provide historical background to the subject, examine the current debate, assess the likelihood of life beyond Earth, and summarize the philosophical implications. Whether cosmic evolution ends in planets, stars and galaxies, or in life, mind and intelligence, will determine the long-term future of humanity. The very search for a "biological universe" affects our world view today, just as Copernicanism and Darwinism affected the short-term and long-term future.

About the Author:

Steven J. Dick has worked as an astronomer and historian of science at the U.S. Naval Observatory since 1979. He obtained his B.S. in astrophysics (1971), and MA and PhD (1977) in history and philosophy of science from Indiana University. Best known as an historian of the extraterrestrial life debate, his doctoral dissertation was published as Plurality of Worlds: The Origins of the Extraterrestrial Life Debate from Democritus to Kant (1982) . He tackled the entire scope of the twentieth century debate in The Biological Universe: The Twentieth Century Extraterrestrial Life Debate and the Limits of Science (Cambridge University Press, 1996) , and its abridgement and update Life on Other Worlds (1998) . The latter works argue that the idea of extraterrestrial life is a world view analagous to the Copernican theory, with widespread implications. Dick has written on these implications, notably in a volume he edited entitled Many Worlds: The New Universe, Extraterrestrial Life and the Theological Implications (2000) . Dick has served as Chairman of the Historical Astronomy Division of the American Astronomical Society (1993-1994), and as President of the History of Astronomy Commission of the International Astronomical Union (1997-2000).

He is currently working on a history of the U. S. Naval Observatory.

Find his books at

- Historical Index - Home -