At the end of the 16th century, the era had fun with the improvement of optical lenses, rapid progress allowing all kinds of fantasies and daring combinations. The invention of optical instruments was in the air, so much so that at the beginning of the 17th century, eyewear manufacturers from the United Provinces were fighting over the invention of the telescope.
Whatever the paternity, it is the perfection of the object and the reading of its images by Galileo (1564-1642) that will turn the world upside down. The academic follower of the intermediate sciences (here, engineering) quickly improves the instrument which he considers at first a philosophical toy, like the microscope will later be. In August 1609, his telescope magnified 8 or 9 times what it aimed for and his demonstration, in Venice, met with great success. From the bell tower of San Marco, we can see Santa Justina in Padua, located about forty kilometers away. Never seen.
To explain the Universe, the doxa of the time only accepted the canonical thought of Aristotelian and Ptolemaic geocentrism, while many scholars refused the new points of view offered by glass lenses. According to them, they are misleading since we see bigger what is small, closer what is far. The telescope is only a new runt of this movement. In their defense, out of the sixty telescopes designed by Galileo, several encountered unfortunate technical problems. The one sent by the Pisan to Kepler (1571-1630) showed the German astronomer square and split stars. Certainly, accessing a new vision requires some adjustments.
Despite everything, the telescope meets its time successfully. At a time when Baroque art solicits sight thanks to a realism dramatized by chiaroscuro, this new instrument satisfies the search for naturalistic precision. The two agree in particular on one point: knowledge of the world passes through the acceptance of a relativity.
The telescope is a new eye that is not free from flaws. The adjustment for the first and the standard for the second make it possible to correct errors without however embracing a perfect vision. The telescope then opens up new philosophical fields, the most emblematic of which is undoubtedly that of Pascal’s two infinities (1623-1662): if we always see more, we never see everything; and can we know the parts without knowing the whole? In painting, it would give a superb chiaroscuro.
As a new object of vision, the telescope also inspires a field of poetic metaphors for moving from one extreme to another, from Earth to Heaven, from the finite to the infinite, from the mortal to the eternal and to explore all the nuances that make it possible to go from one to the other. Galileo’s telescopes, from the most perfect to the most counterfeit, are like the eye subjected to a delimited field of vision. Inevitably, the latter induces a share of vagueness and blindness, infinitely distancing the divine omniscience from the limited perception – by nature or by God – of the human.
