On January 24, our group of five delved into the complex legal and scientific tightrope Galileo walked. We examined the letter from Cardinal Bellarmino, which Galileo interpreted not as a "traffic ticket" or a hard prohibition, but as a warning that still allowed him the intellectual freedom to explore heliocentrism privately.
His interpretation of Bellarmino's letter led to his fierce clash with the Jesuit mathematician Orazio Grassi over the nature of comets. While Grassi correctly used parallax—triangulating distance based on an object’s shift in position—to prove comets were far beyond Earth, he remained anchored to a modified Ptolemaic model.
In a heliocentric frame of mind, Galileo’s private margin notes, in his copy of Grassi’s book, were surprisingly harsh, saying what a “piece of utter stupidity,” “buffoon,” or “bumbling idiot.” Ironically, Galileo’s own theory—that comets were merely optical illusions like the aurora borealis—was incorrect. This raised a question for our group: Is it better to be right for the wrong reasons, or wrong for the right ones?
In his response, The Assayer, Galileo argued that the "book of nature is written in the language of mathematics." He distinguished between primary properties (shape, motion) and secondary properties (taste, odor), a distinction that later influenced Descartes and Locke, and led us to a modern debate: Could AI ever experience qualia, the subjective "feeling" of those secondary properties?
If the "book of nature is written in the language of mathematics," how do we comprehend its text? Today, we have the Copenhagen interpretation of Quantum Mechanics, which states that particles exist in multiple possibilities, governed by the mathematics of probability, and giving rise to the vexing paradox of Schrödinger’s cat. It emphasizes that we can only describe what we measure, without an objective reality existing before observation. Though we may not completely understand this book, are we in a position to disregard the other conclusions of science on evolution, climate change, and even public health?
Claims that natural foods and physical activity prevent disease overlook the reality that life expectancy during the Italian Renaissance, a time when all foods were natural (a beneficial Mediterranean diet) and plenty of physical activity, was roughly half of today’s life expectancy, and infectious diseases were far deadlier before vaccines. Finally, we reflected on the "Galileo Gambit." How do modern deniers of evolution or climate change claim the mantle of the persecuted genius while ignoring the very mathematical and empirical rigor Galileo championed?
We invite you to find out more about the denial of science in our discussion of Mario Livio’s Galileo and the Science Deniers, QB36.G2L658 2020, on February 7, 2026, from 2 PM to 4 PM. (Central Time).
