"Let us hope the key works, because I don't believe he's at home," Professor Franco Pacini joked while fiddling with a lock at Arcetri, a long-shuttered and quite dilapidated villa in the hills above Florence, where Galileo Galilei spent his last days.

Pacini is Director of the Astronomical Observatory in Florence, and is often called "the Carl Sagan of Italy." A few weeks ago, he toured visitors through Galileo's house as a combination public relations and fund-raising effort. Well aware of the pecking order of Italy's historical sites and how capriciously money is allotted to restore them, Pacini hopes Arcetri will be repaired by 2009, which will be the 400th anniversary of Galileo's telescopic discoveries. The International Astronomical Union, based in Paris, also plans to designate 2009 as the year of astronomy.

"This would be a nice place to have meetings in, wouldn't it?" Pacini asked his guests, while standing on a cracked, weed-choked terrace. "Professors and students could gather here and discuss things that Galileo probably was talking about on his death bed, such as 'how were stars born?'"

That Galileo's villa is nearly a ruin is shocking since many, including Albert Einstein, consider him the father of modern science. He's also enjoying a renewed vogue with the publication of Galileo in Rome: The Rise and Fall of a Troublesome Genius by William Shea and Mariano Artigas; and Dava Sobel's Galileo's Daughter which became a best-seller and inspired a PBS-TV documentary.

Yet views differ on Galileo's chief accomplishment. In our anti-clerical age, he tends to become an avatar of secular humanism, which would have surprised the great man as Galileo considered himself a faithful Catholic. His seminal influence on modern astronomy, cosmology and physics is beyond question. Pacini, however, believes Galileo's main legacy is his method of inquiry-specifically, an insistence that true science is based on experimental methodology and mathematics, and that all discoveries must be broadcast.

Galileo Galilei was born in 1564 in Pisa, Italy. His father, a merchant and musician, encouraged him to become a doctor. Even as a young child, Galileo possessed wide-ranging talents. He played the lute and organ exceptionally well, built ingenious toys, and won considerable acclaim for his paintings. At the age of 19, while studying medicine and philosophy at the University of Pisa, Galileo made his first important discovery: the pendulum's law. Observing the sway of a hanging chandelier, he timed the arcs against his own pulse and realized that each swing took the same amount of time, whether the circumscribed arc was large or small.

After returning to the University of Pisa as a professor of mathematics, Galileo built upon his pendulum observations, theorizing that gravity pulls all objects to earth at the same rate of acceleration, regardless of their weight. Whether or not he actually tossed objects off the Leaning Tower of Pisa - a story considered apocryphal by most historians - his ideas about falling bodies were revolutionary and greatly influenced Sir Isaac Newton's laws of motion.

Even today Galileo's theories take a moment to comprehend. For at first glance, they are counterintuitive: shouldn't bigger pendulum swings take longer, or heavier objects fall faster? So, one can well appreciate the controversy Galileo caused in 1609, when he began tinkering with a simple magnifying devise created by a lens grinder in Holland, and ended up amassing scientific evidence that the earth wasn't the center of all heavenly spheres - as both Aristotle and the Roman Catholic Church insisted it was.

Popular myth has it that Galileo simply looked up at the sky one day and "discovered" proof of Copernicus' suspicion that the earth rotated around the sun. In fact, Galileo neither saw this immediately, nor did he make any such allegation. Instead, he first toppled the Aristotelian belief that the moon was a smooth sphere shining with its own light.

Peering through his powerful new telescope, Galileo saw that the moon's surface had craters and mountain ranges, and reflected light from the sun. He also discovered the sun had spots, that Jupiter had planets of its own - the first satellites of a planet other than Earth ever detected - and that there were many, many more stars than previously thought to exist. Patiently assembling such data, Galileo's experimental methodology allowed him to hypothesize that Copernicus was correct: the earth revolved around the sun.

Galileo hurried to make his findings public in Sidereus Nuncius (The Starry Messenger), a slender book, illustrated with his meticulous drawings. The excitable prose sometimes appears immodest, as in "these spots have never been observed by anyone before me." Yet, Galileo is only partially burnishing his reputation. He's mostly lobbying for the analytic method and implying that investigation of nature is the scientist's job. Indeed, in 1611 Galileo even journeyed to Rome to demonstrate his telescope to the papal court.

"Galileo thought things should be believed when you can prove them," noted Pacini. "And that, of course, is what got him into trouble, as there was no concept of intellectual freedom back then."

On the contrary, in reading Sidereus Nuncius, the Catholic Church realized the dangerous theological implications of Copernicus' notions. Taking a literal view of Joshua 10: 10-15, pontiffs believed the Bible taught an earth-centered universe. A pious man, Galileo nonetheless insisted that scriptures must be reconciled with observations of the physical world through mathematical science. Eventually, Galileo was summoned to Rome, and ordered in 1615 to abandon any further study into whether the earth moved.

This makes his subsequent publication of Dialogue Concerning the Two Chief World Systems, something of a mystery. What could Galileo have been thinking as he created a witty conversation between two gentlemen, Salvati (a Copernican) and Simplicio (an Aristotelian), in which Salvati scores nearly all the rhetorical points? Dialogue, in fact, reads as one long argument for the reality of a sun-centered universe.

Rome was not pleased. The papal court added Dialogue to the Index of Prohibited Books and summoned Galileo before an Inquisition, where they forced the 70-year-old, ailing scientist to recant his beliefs. Another probably fanciful story has Galileo rising from his knees after his public disavowal, and muttering under his breath, "E pur si muove" ("nevertheless, it does move"). Following this trial, Galileo lived at Arcetri where he continued his scientific experiments and made sure his findings reached a wide public until his death in 1642.

Professor Pacini suggested that Galileo's scientific discoveries wouldn't have been nearly so influential in his time had they been written in Latin, which only the well-educated elite could read, instead of in the Vulgate, or common Italian. "One of the problems of modern science, you see, is that if we can't figure out a way to popularize it, science will become ever more divorced from culture," Pacini concluded. "Galileo understood this centuries ago."

Barriers and misunderstandings still exist between science and religion, just as they did in Galileo's time. Which is why the John Templeton Foundation is an enthusiastic advocate for interdisciplinary conversation and unfettered research. Like Galileo, Sir John encourages rigorous investigation of the mysteries that still confound both science and theology and is committed to making new findings known throughout the world.

In Possibilities, one of his most recent books, Sir John wrote, "the human race advances on the backs of those rare geniuses who venture into realms of which most of us are afraid." Clearly, Galileo, who changed forever the way we view the universe, was one such genius.

In Memoriam
Pandurang Shastri Athavale, philosopher, social activist and founder of the Swadhyaya Movement, died Saturday, October 25,2003 at age 83. He was the 1997 Templeton Prize Laureate.

Stephen Henderson, a writer based in New York City, contributes frequently to the New York Times, The Baltimore Sun, Town & Country, and Religion News Service, as well as other publications.

Milestones is a publication of the John Templeton Foundation.