This Day in History — Enlightenment

On May 15, 1618, Johannes Kepler discovered his third planetary law, the harmonic law, revealing a precise mathematical relationship between planets and their distance from the Sun. This breakthrough transformed astronomy, strengthened the heliocentric model, and laid the foundation for Isaac Newton’s theory of gravity and modern space science.

Benjamin Franklin, who died on April 17, 1790, was a Founding Father whose influence spanned science, politics, and literature. From Poor Richard’s Almanack to his diplomatic role in securing French support, his innovations and ideas helped shape the United States and left a lasting legacy on the world.

In 1765, French authorities cleared Jean Calas, a Protestant merchant wrongly tortured and executed for allegedly murdering his son. After investigating the case, Voltaire launched a powerful campaign exposing religious prejudice and judicial injustice. The exoneration became a landmark victory for Enlightenment ideals of reason, tolerance, and justice.

After twenty-eight years in exile, Voltaire returned to Paris in 1778 to thunderous applause, greeted as a hero of the Enlightenment. Once censored and banished, the aging philosopher now symbolized reason, tolerance, and reform—his triumphant homecoming marking a cultural turning point that foreshadowed the revolutionary changes soon to reshape France.

Celebrate Feast Day with Thomas Aquinas, one of history’s most influential philosophers and theologians. Born in 1225, Aquinas transformed medieval thought by uniting faith and reason, shaping Christian theology, ethics, and natural law. This post reflects on his life, legacy, and why his ideas continue to matter centuries later.