21/07/2021

In Folha, Viana talks about what Lincoln learned from Euclides.

O décimo sexto presidente dos EUA, Abraham Lincoln. Foto: Pixabay

Reproduction of Marcelo Viana's column in Folha de S.Paulo

Abraham Lincoln (1809–1865) was one of the greatest, if not the greatest, presidents of the United States. A charismatic leader who guided the country through the worst crisis in its history and was assassinated for his role in the abolition of slavery, Lincoln was also an astute politician who knew how to use his humble roots and reputation for honesty. Eloquence was his most powerful political weapon. Several of his speeches, such as the famous "Gettysburg Address," delivered in 1863 in honor of soldiers killed in the Civil War, are among the most influential in American history.

What is less known is the origin of his remarkable oratory skills. Although he revealed the secret in an interview with Reverend J.P. Gulliver, published by The New York Times on September 4, 1864.

Asked how he had acquired such an ability to "say things," the president said that he had received almost no formal education, and added:

“In my law readings I often came across the word 'demonstrate'. At first, I thought I knew its meaning, but then I realized I didn't. I ended up saying to myself: 'Lincoln, you can never be a lawyer if you don't know what 'demonstrate' means'. So I went back to my father's house and stayed there until I understood all the propositions in Euclid's 'Elements'. That's when I knew what 'demonstrate' meant, and I went back to studying law.”

The Greek Euclid lived in North Africa in the Wednesdays century BC. In "The Elements," he gathered and organized the geometry of his time, creating the standard of clarity and rigor of reasoning that endures in mathematics to this day. It was in this work by Euclid, one of the most influential in the history of humanity, that the brilliant orator found inspiration.

Gulliver made no secret of his admiration: “Mr. Lincoln, your success is no longer a cause for astonishment. It is the legitimate result of appropriate causes. With your permission, I would like to recount this fact publicly. It will be very important in motivating young people towards mathematical culture, which all minds absolutely need to possess.” And he added: “Euclid, well studied, would rid the world of half its calamities, banishing half the nonsense that deceives and curses our days. I always thought that 'Elements' would be one of the best books for the Bar Association library, if they could get people to read it.”

To read the full text, visit the newspaper's website.