Doubt is the father of discovery.
Galileo paid a heavy price for his doubt. It is inspiring to know that he held to its efficacy.
The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts.
— Bertrand Russell, philosopher, mathematician, author, Nobel laureate (1872-1970)
The greatest obstacle to discovering the shape of the earth, the continents and the ocean was not ignorance but the illusion of knowledge.
— Daniel Boorstin
To really appreciate the profundity of this quote you have to think back to Galileo (1564 – 1642) and his epic battle with the Roman Catholic church over the nature of our solar system. Although Copernicus (1473 – 1543) had developed the heliocentric theory a hundred years earlier, the “prevailing wisdom” maintained that the earth was at rest at the center of the universe while the sun and the planets revolved around it.
But Galileo had a telescope — and became convinced that Copernicus was right. He championed the sun-centric “theory” at great personal risk. He was declared a heretic, forced to recant, and spent the last years of his life under house arrest. The church did not lift its ban on the general prohibition against works advocating heliocentrism until 1758.