Ruggero Giuseppe Boscovich

Born: 18 May 1711 in Ragusa, Dubrovnik Republic (now Dubrovnik, Croatia)
Died: 13 February 1787 in Milan, Hapsburg Empire (now Italy)

First let us note different versions of Ruggero Giuseppe Boscovich's name. There are at least three commonly used: the Italian version Ruggero Giuseppe Boscovich, the Croatian version Rudjer Josip Boskovi'c, and the English version Roger Joseph Boscovich. Two less common forms are the French version Rogér Joseph Boskovic and the Latin version Rogerio Josepho Boscovich. Ruggero's father was Nikola Boscovich, a merchant from Dubrovnik, and his mother was Pavica Bettera, the daughter of Baro Bettera who was also a merchant. Baro Bettera came from Bergamo in Italy, so Boscovich, the subject of this biography, was half Italian; he lived for a large part of his life in Italy and some today consider him an Italian. Nikola and Pavica were well educated and fairly well off. They lived in a three-storeyed family house just off the main street of Dubrovnik. Certainly they needed a large house for Ruggero was the eighth of the nine children in the family which consisted of six boys and three girls.

The Dubrovnik Republic was, in the first few years of Boscovich's life, isolated from the wars and fighting which went on around it. The surrounding area was continually fought over with Turks holding much of the district. Austrians, in alliance with Venetians, fought the Turks over the territory. The Turks and the Russians also fought close to the city and in 1716 the Austrians tried to surround Dubrovnik. Despite appearing in the middle of a war zone, the city was peaceful and it is doubtful whether the young Boscovich was aware of the fighting. He certainly was aware, however, of his father's ill health for Nikola died when Boscovich was ten years old having been confined to bed during these ten years. Boscovich's mother Pavica was a very active and able woman who continued to keep the family happy despite the health problems of her husband. They were religious with one of the girls becoming a nun, two of the boys Jesuit priests, and another a Dominican friar. Of the nine children, only Boscovich's eldest sister Mare married.

The first education that Boscovich received was from the local priest who taught him the basics of reading and writing. At the age of around nine he attended the local Jesuit Collegium Ragusinum where he received formal education [5]:-

In his fifteenth year ... he left his family and friends and native town. Driven by fervent piety, ambition and a love of learning and either influenced in the choice of his future career by his family or by his Rector and teachers at the Ragusinum, who were aware of the exceptional qualities of his mind, or independently realizing his vocation, he offered himself for the protracted and severe religious and intellectual training by the Jesuits in Rome.

Boscovich left Dubrovnik on 16 September 1725, crossed the Adriatic, then travelled by stage-coach to Rome. He became a novice in S Andrea delle Fratte where he spent two years, then studied at the Collegium Romanum on the north side of the Piazza del Popolo in Rome [1]:-

He was extraordinarily sharp of mind, comprehensive in intelligence, and tireless in application - in short, an outstanding student. He learnt science in a way characteristic of his later career, through independent study of mathematics, physics, astronomy, and geodesy.

He had completed his course by 1732 but then was required to teach in Jesuit schools for five years. Because he was such an outstanding student he did not have to teach in smaller schools, but spent most of this time teaching in the Collegium Romanum. It was a punishing schedule and under the pressure his health broke down on several occasions. He continued studying during these years reading Newton's Opticks and Principia from 1735 onwards. He also began making astronomical observations and observed the transit of Mercury on 11 November 1736, publishing his results in De Mercurii novissimo infra solem transitu (1737). Also in 1737 he published a mathematical work on spherical trigonometry Trigonometriae sphaericae constructio. By 1737 he had completed his initial training and could embark on a course in theology which would lead to entry into the priesthood. He remained at the Collegium Romanum, however, and continued to teach mathematics and logic there while undertaking deep scientific research in addition to studying theology. Little wonder that his health became poor, but again he recovered to continue with the punishing schedule.

He was appointed professor of mathematics at the Collegium Romanum in 1740, although at this stage he was still undertaking theology training. In fact the year 1740 also marked the advent of a new Pope, Benedict XIV, and he would soon involve Boscovich in important roles. In 1742 Boscovich was asked to give an opinion on the cracks which had been evident in the dome of St Peter's for many years. He recommended that iron rings be placed round the dome and indeed this was done between August 1743 and September 1744. (Poleni was also consulted about the problem and gave the same advice.) The Pope was well pleased with Boscovich's advice and he was given various other architectural tasks. His training to be a priest achieved a successful conclusion in 1744 with his ordination. However his interests did not lie in the priesthood but rather in his role as professor of mathematics [5]:-

He had developed from a somewhat melancholy, outwardly modest young man with ambitions, a novice of promise, timid in person, but bold in speculative flights, into a mature man, sure of himself, with a commanding personality. He was being increasingly considered as an original intellectual who could eloquently defend his ideas. He was a scholar with a considerable reputation among the many brilliant intellects of Rome. He had even been heard of abroad. He was an enviable young expert with a distinguished career before him.

He was one of the first in continental Europe to accept Newton's gravitational theories and he wrote 70 papers on optics, astronomy, gravitation, meteorology and trigonometry. His main work was in mathematical physics. In his study of the shape of the Earth he used the idea of minimising the sum of the absolute values of the deviations so making an important early contribution to statistics. His solution to this minimising problem took a geometric form. Boscovich was the first to give a procedure to compute a planet's orbit from three observations of its position and he also gave a procedure for determining the equator of a planet from three observations of a surface feature.

Boscovich published Theoria philosophiae naturalis reducta ad unicam legem virium in natura existentium in 1758. He criticised Newton's concepts of absolute space and time, absolute motion, action-at-a-distance, and atomism. His own ideas on atomism are described in detail in [36] where the author writes:-

His idea of atoms is opposed against the older Lucretian theory that atom is an extended, hard and elastic body. He intended to explain all natural phenomena by postulating nonextended atom and the law of force between atoms. The influence of Boscovich's theory was wide in the eighteenth and nineteenth centuries especially in Britain. Boscovich assumed point-atoms in opposition to hard, extended atoms. He also postulated the force between atoms to be repulsive at very small distances, attractive and repulsive alternately with increasing distance and attractive, following the law of gravitation, at macroscopic distances. Based on these assumptions he intended to account for the properties of matter. His ideas spread in the eighteenth and nineteenth centuries. His atoms were considered from the different points of view, namely, the point-atoms interacting at a distance and those as singular points in the field of force. The meaning of his ideas in the history of atomism is stated.

In [19] Manara writes about Boscovich's work on continuity and the nature of space:-

In our opinion the great genius, versatile intelligence, and originality of this Dalmatian physicist and mathematician warrant the remembrance and the study of his works and thought. ... In a treatise [held in the Catholic University at Brescia] Boscovich presents his own ideas concerning continuity, which is seen as a property of what is usually called geometric space. Earlier we analysed his treatise from this point of view in an attempt to cast light upon Boscovich's ideas concerning the question, much debated at the time, of what one might call 'the nature and constitution of the geometric continuum', a problem associated with the question of geometric indivisibles, which originated with the works of Bonaventura Cavalieri and was debated at length. Let us briefly summarize what we feel to be the fundamental points of Boscovich's thoughts concerning these topics:

  1. Boscovich accepts the Aristotelian definition of continuous quantity; according to that definition, the continuum is characterized by the fact that the parts have a common end.
  2. In this conception, the point is considered an 'end' of the line, and is therefore indivisible and of a nature different from that of the segment.
  3. The geometric continuum is infinitely divisible; segments, no matter how small or how large, can arise.
  4. There do not exist true infinitesimal segments.
  5. The law of continuity holds in all cases for geometric curves, which cannot have stopping points or discontinuities.
Boscovich was therefore able to conceive of matter as made up of nonextensive material points acted upon by forces that not only are attractive, as determined by Newton's law of gravitation, but can also become repulsive at short distances; this explains the phenomenon of cohesion no less than that of the impenetrability and solidity of matter.

In a related paper [17] Homann writes:-

Boscovich's implicit, or working, philosophy of mathematics centred on a geometry that was axiomatically Euclidean, abstracted from phenomenal experience, and able to describe, in an approximate manner, phenomena on a macroscopic level. This geometry admitted extension by elements, such as ideal points, with no correspondent in phenomenal experience. In appropriate circumstances, the geometry of the continuum can describe physical reality that, on the microscopic level, is discontinuous and finite.

It has always proved difficult for deep thinkers about science to work within the Church. Although Boscovich was a staunch Christian, he found his position in Rome becoming rather uncomfortable. He requested permission to travel and this was granted. He set off for Paris in 1759; details of his visit are given in [35]. He had already established good relations with members of the Academy such as La Condamine and Lalande who had met Boscovich during their travels around Italy (see [21]). Boscovich had submitted a memoir for the Grand Prix of the Academy of Sciences in 1752 on his study of Saturn and Jupiter. The prize was given to Euler but Boscovich had received an honourable mention.

Boscovich, who attended meetings of the Academy of Sciences during his stay in Paris, was known in France for his studies on astronomy, the aurora borealis, and the measurement of the arch of the meridian through Rome and Rimini which he had carried out in 1739. He became friendly with Clairaut who admired his vast culture and his dynamic personality; they corresponded between May 1760 and July 1764 after he left Paris. After six months in Paris, Boscovich went to London where he was elected to the Royal Society on 15 January 1761. While in England he met Thomas Simpson in 1760, and he posed a problem in least deviations regression to Simpson (see [33]). He also encouraged the Royal Society to send an expedition to observe the transit of Venus which was to take place in June 1761.

Boscovich planned to be in Istanbul to observe the transit himself, but due to the Venetian ambassador to Istanbul who was his travelling companion, he arrived too late to observe this important astronomical event. He became professor of mathematics at Pavia in 1764 and was director of Brera Observatory. He did much work on improved optical devices for the Observatory and made important advances on achromatic lenses. Proverbio writes [27]:-

In November of 1769, Boscovich was called from Pavia to teach astronomy and optics at the Palatine Schools in Milan. In the period between 1769 and 1771, he intensified his research activities in the fields of astronomy and optics at the Brera Observatory, which he himself had designed. Towards the end of 1771, the Vienna government, while carrying out its general reorganization of university studies in Pavia and Milan, advanced certain observations regarding the operation of the Brera Observatory. This criticism aroused more than a few perplexities in scientific circles, particularly in Lalande, one of Boscovich's assiduous correspondents. Boscovich replied to these observations in a long memorial [Risposta] that remained to all intents and purposes unknown until 1927.

He was invited by the Royal Society to lead an expedition to California in 1769 to observe the next transit of Venus. However politics prevented him from carrying this out. Things now took a turn for the worse. He was out of favour with his colleagues and in 1772 he was removed from his post as director of Brera Observatory. He resigned his professorship in protest. Being a Jesuit meant that he was out of favour since there had been strong moves against the Jesuits for some time. The Portuguese crown had expelled the Jesuits in 1759 and Boscovich had been openly critical of the lack of support given by Rome for his Order. King Joseph I of Portugal considered the Jesuits to be too political and to be interfering with his ambitions. France had made the Jesuits illegal in 1764, and in 1767 Spain and the Kingdom of the Two Sicilies had followed suit. Clement XIV, educated by the Jesuits and friendly towards them, was elected Pope on 18 May 1769. He had to face up to the Jesuit issue and to try to save the break-up of the Roman Catholic Church he dissolved the Jesuits on 21 July 1773. What was Boscovich to do?

Paris was where he had travelled to before to escape from problems and he sought to do so again. In 1773 he went to Paris to take up the post of Director of Optics for the French Navy. Of course this was not the sort of post that the French would be happy to see held by a foreigner, so Boscovich became a French citizen. However he did not find France as pleasant as he had hoped, for he became involved in a number of disputes. As long before as 1746 he had devised a method of determining the orbit of a comet from three observations of its position. Now the young ambitious Laplace attacked his methods. He was also involved in a priority dispute over some of the surveying instruments he had devised. He tried to enjoy a quiet life in the country but decided to return to Italy in 1782 to prepare his works for publication. He published a five volume treatise of his contributions in 1785 but the work involved in editing and correcting this had a negative affect on his health. He began to lose his mental faculties but, perhaps fortunately, died of a lung disease before these had deteriorated too much.

Finally let us look at Boscovich's scientific methodology. This is discussed in [15] in which Grmek writes:-

In statements pertaining to methodology he insists on the limits and the relativity of all human knowledge; he describes three sources of knowledge; he defines criteria of the scientific soundness of statements; finally, he deals with the problem of induction in a critical manner and sets out a particular heuristic procedure (the 'method of decipherment'). Boscovich describes with clarity the logical procedure by means of which he constructs his 'new world'. Although this procedure is perfectly clear, it corresponds only in part to his actual approach. If Boscovich accepts in his statements on scientific methodology neither pure rationalism, nor Baconian induction, and appears as an adept of the experimental method, he has only slight recourse to this method.

Article by: J J O'Connor and E F Robertson

August 2006

MacTutor History of Mathematics