Tag Archives: Galileo

June 22, 1633 (a Wednesday)

Galileo

On this date, the Florentine-Italian astronomer Galileo Galilei was compelled by the Roman Inquisition to recant the theory he held that  Earth travels around the sun.

March 31, 1596 (a Sunday)

René Descartes

On this date, the French mathematician, anatomist, physiologist, and philosopher René Descartes was born in La Haye in the region of Touraine, France. He is often regarded as the first modern thinker to provide a philosophical framework for the natural sciences as these began to develop. In his Discourse on the Method of Rightly Conducting One’s Reason and Of Seeking Truth in the Sciences (1637) he attempts to arrive at a fundamental set of principles that one can know as true without any doubt.

Descartes is also known for the mind/body dualism he first articulated in his De homine (Treatise on Man), which he completed in Holland about 1633, on the eve of the condemnation of Galileo. When his friend and frequent correspondent, Marin Mersenne, wrote to him of Galileo’s fate at the hands of the Inquisition, Descartes became concerned for his own safety and refused to have De homine printed. Consequently, the first edition of this work was not published until 12 years after the author’s death.

Figure 1 from Descartes’ De homine (1664), depicting the human heart.

According to Descartes’ principle of dualism, the body works like a machine, has the material properties of extension and motion, and follows the laws of physics. The mind (or soul), on the other hand, is described as a nonmaterial thinking entity that lacks extension and motion, and does not follow the laws of physics. Descartes argued that only humans have minds, and that the mind interacts with the body at the pineal gland. [He chose the pineal gland because it appeared to him to be the only organ in the brain that was not bilaterally duplicated and because he believed, erroneously, that it was uniquely human.] In De homine, he wrote:

I suppose the body to be nothing but a statue or machine made of earth, which God forms with the explicit intention of making it as much as possible like us…

William Harvey’s recent discovery that the heart acts as a pump to circulate the blood had supplied additional arguments in favor of Descartes’ mechanical theory – in fact, Descartes probably did much to popularize the discovery. The Cartesian dualism set the agenda for philosophical discussion of the mind/body problem for many years after Descartes’ death.

March 5, 1616 (a Saturday)

Cardinal Robert Bellarmine

On this date, the Copernican theory was declared “false and erroneous” by the Decree of the Holy Congregation of the Most Illustrious Lord Cardinals in charge of the Index (more commonly known as the Decree of the Index) written by Cardinal Robert Bellarmine, and issued by the Catholic Church in Rome. Further, no person was to be permitted to hold or teach the theory that the Earth revolves around the sun. When Galileo subsequently violated the decree, he was put on trial and held under house arrest for the final eight years of his life.

February 15, 1564 (Julian calendar/old style: a Tuesday)

Galileo

On this date, the Florentine-Italian astronomer Galileo Galilei was born in Pisa, Italy. Galileo made a good discovery great. Upon hearing at age 40 that a Dutch optician had invented a glass that made distant objects appear larger, Galileo crafted his own telescope and turned it toward the sky. He quickly discovered that our Moon has craters, that Jupiter has its own moons, that the Sun has spots, and that Venus has phases like our Moon. Galileo, who lived to 1642, made many more discoveries. He claimed that his observations only made sense if all the planets revolved around the Sun, as championed by Aristarchus and Copernicus, and not around the Earth, as was commonly believed then. The powerful Roman Inquisition made Galileo publicly recant this conclusion, but today we know he was correct.

February 13, 1633 (a Sunday)

Galileo facing the Roman Inquisition.

On this date, Italian philosopher, astronomer and mathematician Galileo Galilei arrived in Rome to face charges of heresy for advocating Copernican theory, which holds that the Earth revolves around the Sun. Galileo officially faced the Roman Inquisition in April of that same year and agreed to plead guilty in exchange for a lighter sentence. Put under house arrest indefinitely by Pope Urban VIII, Galileo spent the rest of his days at his villa in Arcetri, near Florence, before dying on January 8, 1642.

Today, Galileo is recognized for making important contributions to the study of motion and astronomy. His work influenced later scientists such as the English mathematician and physicist Sir Isaac Newton, who developed the law of universal gravitation. In 1992, the Vatican formally acknowledged its mistake in condemning Galileo.

January 20, 1633

Galileo

On this date, Galileo, at age 68, left his home in Florence, Italy to face the Inquisition in Rome. After two weeks quarantine (because of the plague) just outside Rome, he arrived there on 13 February.

By 22 June 1633, he had buckled under the threats and interrogation by the Inquisition, and renounced his “belief” that the Earth revolved around the Sun.

Aside from his theoretical works, Galileo made several contributions to “technology” such as an improved telescope, a thermometer, a military compass and many many others. So great was his legacy that he was called by Einstein the “father of modern science.”

October 31, 1992 (a Saturday)

Galileo facing the Roman Inquisition.

On this date, the Vatican finally admitted erring for over 359 years in formally condemning Galileo Galilei for entertaining the scientific truth that the Earth revolves around the sun, which the Roman Catholic Church had long denounced as anti-scriptural heresy. After 13 years (!) of inquiry, the Pope’s commission of historic, scientific and theological scholars brought the pope a “not guilty” finding for Galileo. Pope John Paul II himself met with the Pontifical Academy of Sciences to help set the record straight.

On the morning of June 22, 1633, at age 69, Galileo had been ordered by the Roman Inquisition to repent and spend the last eight years of his life under house arrest. His formal sentencing had concluded:

And, so that you will be more cautious in future, and an example for others to abstain from delinquencies of this sort, we order that the book Dialogue of Galileo Galilei be prohibited by public edict. We condemn you to formal imprisonment in this Holy Office at our pleasure.

As a salutary penance we impose on you to recite the seven penitential psalms once a week for the next three years. And we reserve to ourselves the power of moderating, commuting, or taking off, the whole or part of the said penalties and penances.

This we say, pronounce, sentence, declare, order and reserve by this or any other better manner or form that we reasonably can or shall think of. So we the undersigned Cardinals pronounce.

Galileo was a seventeenth-century Italian mathematician, astronomer and physicist remembered as one of history’s greatest scientists. However, Pope John Paul II did not specify a penalty or penance for the Church.

October 24, 1632

Anton Van Leeuwenhoek

On this date, the Dutch microscopist Antony van Leeuwenhoek was born.  He made some of the most important discoveries in the history of biology.  During his lifetime, Leeuwenhoek ground over 500 optical lenses and created over 400 different types of microscopes, only nine of which still exist today.  Leeuwenhoek was the first person to see bacteria, free-living and parasitic microscopic protists, sperm cells, blood cells, microscopic nematodes and rotifers, and much more. His researches on lower animals refuted the doctrine of spontaneous generation, and his observations helped lay the foundations for microbiology.

It is worth noting that Leeuwenhoek’s early discoveries in the field of microbiology are analogous to Galileo’s early discoveries in the field of astronomy. Both men used the newly improved optical technologies of their day to make major discoveries that entirely overturned traditional beliefs and theories in their respective fields, and both men were initially met with strong skepticism and resistance to the inevitable conclusions to which their discoveries led. Ultimately, Leeuwenhoek was more fortunate than Galileo in that his discoveries were eventually widely accepted and applauded in his lifetime, whereas Galileo’s were not. In addition, Leeuwenhoek’s main opposition was from the scientific community, not the religious community, because Holland was freer of religious persecution than many other European nations at the time. Galileo, for example, faced strong religious persecution.