A foundational text that articulated the modern scientific method turns 400

This October marks the 400th anniversary of the publication of The Assayer (Il Saggiatore, in Italian) by Galileo Galilei (1564–1642). A treatise intended to address a major controversy on the nature of three comets observed in Europe in 1618, the book came to represent a major landmark in the history of science. Contained in Galileo’s discussions of “science as a method of demonstration and reasoning capable of human pursuit” is an articulation of the scientific method as we now know it.
Some have “advanced ridiculous and impossible opinions against me,” writes Galileo, dramatically, in the book’s opening, referring specifically to criticisms leveraged by the Jesuit priest and mathematician Orazio Grassi. Writing under the pseudonym Sarsi, in 1619 Grassi had published Libra Astronomica ac Philosophica, which sought to refute Galileo’s claim that the comets could be visual illusions rather than celestial bodies . (Grassi was later proven right.) Thus, “forced to act by this unexpected and uncalled-for treatment,” Galileo continues, “I break my previous resolve to publish no more.”

The Assayer was written as a letter to Virginio Cesarini, an Italian poet and chamberlain to Pope Gregory XV and his successor Pope Urban VIII, to whom Galileo dedicated the book and under whose pontificate the astronomer was trialed 10 years later. It contains, among other prescient observations, a revelatory passage about the mathematical intelligibility of nature. “Philosophy is written in this grand book, the universe, which stands continually open to our gaze,” Galileo writes. “But the book cannot be understood unless one first learns to comprehend the language and read the letters in which it is composed. It is written in the language of mathematics, and its characters are triangles, circles, and other geometric figures without which it is humanly impossible to understand a single word of it; without these, one wanders about in a dark labyrinth...”

...Galileo also stamped another indelible idea in The Assayer, one with consequences for the study of mind and matter that have percolated through the centuries and continue to affect 21st-century consciousness studies. Toward the end of the book, he writes: “Without the senses as our guides, reason or imagination unaided would probably never arrive at qualities like these. Hence I think that tastes, odors, colors, and so on are no more than mere names so far as the object in which we place them is concerned, and that they reside only in consciousness.” Galileo contrasts the “primary phenomena of motion and touch” with sensations, which he regards as “secondary qualities” with “no real existence save in us.” Having programmatically excluded subjective experience from the purview of science, we are still struggling to untie the Galilean knot that is the hard problem of consciousness...

...The book is also an example of epistemic humility in the face of dogmatic opinions, appeals to authority, and the profligacy of logical argumentation. “[W]e must resort to experiments for settling such questions...”

Week beginning on October 08, 2023: 418.53 ppm
Weekly value from 1 year ago: 415.39 ppm
Weekly value from 10 years ago: 393.58 ppm
Last updated: October 15, 2023