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Achillini, Alessandro

Agricola, Georgius

Alberti, Leone Battista



Babington, John

Baif, Lazare de

Baldi, Bernardino

Baliani, Giovanni Battista

Barocius, Franciscus

Benedetti, Giovanni Battista

Berga, Antonio

Biancani, Giuseppe

Borelli, Giovanni Alfonso

Borro, Girolamo

Boyle, Robert

Branca, Giovanni

Buonamici, Francesco

Buteo, Johannes

Cardano, Girolamo

Casati, Paolo

Castelli, Benedetto

Cataneo, Girolamo

Ceredi, Giuseppe

Ceva, Giovanni

Cicero, M. Tullius

Commandino, Federico

Delfino, Federico

Descartes, Rene



Fabri, Honore

Foscarini, Paolo Antonio

Galilei, Galileo

Gassendi, Pierre

Ghetaldi, Marino

Giphanius, Hubert

Guevara, Giovanni di

Heron Alexandrinus

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Jordanus de Nemore

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Manuzio, Paolo

Marci of Kronland, Johannes Marcus

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Monantheuil, Henri de

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Newton, Isaac

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Schreck, Johann Terrenz

Stelliola, Niccolò Antonio

Stevin, Simon

Tartaglia, Niccolò

Thomaz, Alvaro


Torricelli, Evangelista

Valerio, Luca

Varro, Michel

Vitruvius Pollio

Wolff, Christian von

Borelli, Giovanni Alfonso
born on 28.1.1608 in Naples, died on 31.12.1679 in Rome, Italian mathematician, physicist, astronomer and physiologist

In 1630 it was first reported that Borelli studied mathematics from Galileo’s pupil B. Castelli in Rome, primarily Euclid’s Elements and Apollonio’s Conics. Borelli presumably came to Rome in 1628, where he had connections to Tommaso Campanella, whom he may have met in Naples in 1626, and he probably introduced him to Castelli, with whom Borelli studied along with Torricelli. Borelli’s younger brother Filippo accompanied T. Campanella when the latter had to flee to Paris in 1634, and assisted Campanella in publishing his works there. During the period when Galileo’s Dialogo appeared and the subsequent trial, Borelli was in Rome, but never made Galileo’s personal acquaintance. Thanks to Castelli’s recommendation, Borelli was appointed to the university in Messina, at which he instructed mathematics and astronomy from around 1635 until 1656. When a successor for the professorship of mathematics at the University of Pisa was being sought in 1640, Castelli wrote two letters to Galileo, in which he heartily recommended Borelli for this position. However, Galileo chose Vincenzo Renieri, who occupied this position until his death in 1647. In 1642 the senate of the university in Messina commissioned Borelli to travel to the leading Italian universities in order to acquire good instructors for the university in Messina. During this trip he was in Naples to meet with Marco Aurelio Severino and perhaps to renew an old friendship with Severino; he also visited Castelli in Rome. It is certain that Borelli was also in Tuscany; however, he was too late to meet with Galileo, who had died shortly before. Borelli spent some time in Florence, where he met with Viviani; next he went to Bologna, where he greatly impressed Bonaventura Cavalieri. Before Borelli finally returned to Messina he was also in Padua and possibly also in Venice. Borelli’s reputation had been spreading through Italy since around 1643, although he had not yet published anything himself. His opinions on mathematics, physiology and astronomy commanded great respect. He was considered to be the best Italian mathematician after B. Cavalieri, as whose successor Borelli was to be appointed in Bologna in 1650. Since this appointment never came through, however, Borelli went to Pisa in 1656, where he taught until 1666 and had his own anatomical laboratory. One of his students there was Marcello Malpighi, and an enduring friendship ensued. In 1657 Borelli became a member of the Accademia del cimento founded in that year, in which he played a significant role. When the academy was closed in 1667, Borelli returned to the university in Messina, where he joined the movement against the Spanish. From 1672 Borelli was persecuted for political reasons and forced to flee Sicily. From 1674 he was in Rome and soon belonged to the inner circle of the Swedish Queen Christina, who had converted to Catholicism. Because all of his efforts to obtain an academic office in Rome failed, his financial plight forced him to accept the hospitality of the Piarist order in Rome in September 1677, in whose school he instructed novices until his death.
Borelli’s significant achievements in physics, physiology and mathematics are unjustly overshadowed by the meaning Isaac Newton has taken on in the history of physics. Borelli first attracted attention when he, in a tract about the causes of a fever epidemic in Sicily in 1649, publicly expressed the opinion that this disease had neither a meteorological nor an astrological cause, but rather a chemical origin, which exerted an external influence on the body; at the same time he described an effective medicine against this fever, namely sulfur. In his 1658 edition of Euclid’s works, Euclides restitutus, Borelli provides a new formulation for the parallel postulate, without being able to prove this reformulation, however; he also attempts to give the theory of proportion a new, improved foundation. In 1658, Borelli edited the as yet unknown Books V – VII of Apollonio’s Conics, for the first time from an Arabic source. Based on his observations of a comet that appeared in 1664, he was the first to describe the trajectory of a comet as an ellipse (Del movimenti della cometa ... di dicembre 1664 Pisa 1665). To explain the movements of the planets, (Theoricae mediceorum planetarum ex causis physis deductae Florence 1666), Borelli pursues the theory of elliptical trajectories by I. Boulliaus, which he also uses to explain the movements of the moons of Jupiter. The planets, floating in ether, are supposedly led around in a circle by solar radiation, whereby the resulting centrifugal forces are supposedly compensated for by the planets’ own movement toward the sun. His two main works of physics, De vi percussionis (1667) and De motionibus naturalibus a gravitate pendentibus (1670) contain many important physical answers to questions open at the time, which he investigated experimentally and mathematically over the course of many years, as for instance, the general problem of movement, gravity, magnetism, the flux of liquids, the oscillation of solids and the movements of pendula. In his main physiological work, De motu animalium (Rome 1680/81) Borelli lays the foundation of what is known as iatrophysics (historically, the preliminary stage of biophysics), in which he explains the movement of living beings using the movements of muscles and the associated leverage in the joints and at the bones. He attempts to explain the contractions of muscles by presuming chemical reactions in the muscles that lead to their contraction. For this insight Borelli is due the honour of being considered the founder of biophysics.

Digital texts (1 texts)



De motionibus naturalibus a gravitate pendentibus