Essential Thinkers #18 Galileo Galilei: The Quest for Knowledge Amidst Religious Dogmatism

Italian philosopher, astronomer, scientist and mathematician, Galileo Galilei (1564 – 1642) is probably best remembered for his work in support of Copernicus’ heliocentric theory of the solar system. For the sake of his life, Galileo recanted his views in 1633, admitting that the earth did not spin on its own axis. It is unlikely that the recantation was sincere and he nevertheless remained under house arrest.

In 1608 the Dutchmen Lippershey invented the telescope. Within two years Galileo used it to dramatic effect, showing by his astronomical observations that the Ptolemaic or geocentric theory which held that the Earth was at the centre of the universe, was seriously flawed. Galileo also observed that the Milky Way was in fact made up of many millions of individual stars. He observed the phrases of Venus and discovered the moons of Jupiter, which had theological experts up in arms. Indeed, Galileo’s findings attracted such sharp criticism, both from secular and ecclesiastical quarters that he felt compelled to offer, both in his defence and in reply to his critics, the Letter to the Grand Duchess Christina in 1615. In the Letter, Galileo argues that scientific and theological matters should not be confused. Science could not cast doubt on religious doctrine, only strengthen it. Nonetheless he was condemned by the Inquisition, first in private communication in 1616 and later in 1633, when he publicly recanted.

Although his work was instrumental in bringing the Copernican system into prominence, Galileo was far more than just an astronomer. Much of his important work lay in dynamics and the principles of movement. He was the first to discover the law of falling bodies, or constant acceleration, published after his recantation and whilst still under house arrest in 1638, in his Discourse on Two New Sciences.

Moreover, what would later be Newton’s celebrated first Law of Motion was directly taken from Galileo’s principle of inertia, namely that a body moves in a straight line with uniform velocity unless acted upon.

This principle was important in helping to support the Copernican theory. Critics of Copernicus had claimed that if the heliocentric theory were true, then a falling body should not fall in a straight line, but in fact land somewhat to the west of the point from which it was dropped, on account of the eastwise rotation of the Earth. It had been proven by experiment that this was not the case, a result which led many to dismiss Copernicus as wrong even if they did not share the religious reasons for dismissing him. It took Galileo’s work in dynamics to show why the prediction was not fulfilled. Simply put, the falling stone retains the rotational velocity of the Earth.

Philosophically, Galileo held that “the book of nature is written in the language of mathematics.” He was heavily influenced by Greek philosophy and a great admirer of Archimedes. He also maintained, like John Locke, that there was a metaphysical distinction between the primary and secondary qualities of bodies. The former are essential and inherent in objects, whereas the latter exist only insofar as they cause certain effects in the minds of observers. Undoubtedly, Galileo was a great thinker who risked much in the pursuit of truth, helping to set free the quest for knowledge from the chains of religious dogmatism.

[Summarized from Philosophy 100 Essential Thinkers by Philip Stokes, 2012]

Lord, Give Us Today Our Daily Idea(s)

Renaissance Innovators who Challenge Orthodoxies (Nonconformists Wins)

Perhaps the first thing that comes to mind when we think about Renaissance innovators is their contrarian spirit. It was a time when people began to ask sceptical questions that had never been asked before, and to challenge deeply entrenched beliefs that had long been taken for granted. For examples:

Copernicus, Galileo, and Kepler asked:

“What if the Earth is not the centre of the Universe? What if it revolves around the Sun along with the other planets?”

Martin Luther asked:

“What if the papacy and the dogma of the Roman Catholic church are actually wrong? And what if we could read the Bible and listen to sermons in our own language, instead of in Latin?”

Petrarch asked:

“What if a person can achieve great things in this world without being ungodly? What if God wants us to use the intellectual and creative powers he gave us to their fullest potential?”

Andreas Vesalius asked:

“What if the dominant theories of human anatomy that have been unassailable for a thousand years are fully misguided? What if the human body functions completely differently than we have been taught? And what if we started dissecting some dead bodies to find out the truth?”

Paracelsus asked:

“What if everything we know about medicine is nonsense? What if certain chemicals and minerals, used in the right dosage, would be a far better way to cure illnesses than traditional practices? What if nature could teach us more about medicine than ancient books from Greece and Rome?”

Machiavelli asked:

“What if politics has nothing to do with theology or morality? What if it’s simply about using all means – fair and foul – to retain power?”

Descartes asked:

“What if all of our traditional systems of thinking, most of which are founded upon Aristotle’s ideas, are false? What if we set out to build a new philosophical system from the group up, by first doubting everything we think we know?”

Isaac Newton asked:

“What if conventional concepts of physics, gravity, and motion are inconsistent with reality? What if we need new laws and mathematical models for understanding mechanics?”

Filippo Brunelleschi and Leon Battista Alberti asked:

“Why can’t a painting be less like wall decoration and more like a window into the nature world? What if we used mathematical and optional principles to imitate objects so accurately that they look entirely real?”

Christopher Columbus asked:

“What if we could get to the East Indies much faster by sailing west instead of east and circumnavigating the globe?”

Amerigo Vespucci asked:

“What if the Earth has a much larger circumference that we learned from Ptolemy’s cartography? What if these lands Columbus has newly discovered are not the Indies at all, but in fact another whole continent – a New World?”

Almost by definition, the Renaissance revolutionaries were nonconformists who were willing to contest previously held truths – beliefs and assumptions that had been accepted as absolute truth for perhaps a thousand years or more – and to reinvent their worldview completely from scratch. Many of them were branded as heretics or lunatics. Yet their propensity to break the chains of precedent and to challenge conventional thinking became the basis for a whole string of breakthrough discoveries and new philosophies that literally changed our world.

[Questions are taken from The 4 Lenses of Innovation (2015) by Rowan Gibson. Title mine]

Lord, Give Us Today Our Daily Idea(s)