Johannes van Heeck, (Deventer 2 February 1579 – presumably Sant'Angelo Romano c.1620), (also known as Johann Heck, Joannes Eck, Johannes Heckius, Johannes Eckius and Giovanni Ecchio) was a Dutch physician, naturalist, alchemist and astrologer. Together with Prince Federico Cesi, Anastasio de Filiis and Francesco Stelluti, he was one of the four founding members of the Accademia dei Lincei,Philip Ball, Curiosity: How Science Became Interested in Everything, University of Chicago Press, 2013 p.64 the first learned society dedicated to understanding of the natural world through scientific enquiry.

Family background

Johannes van Heeck was one of five children in a family of wealthy merchants. His father was Willem, son of Willem van Heeck, and his mother was Lutgardt, daughter of Gerrit. Between 1587 and 1591 his father, a Catholic, was one of Deventer's political leaders, elected senator and consul in 1589. For this reason, when Protestant forces under Maurice of Nassau took the city in 1591, Willem van Heeck was fined 150 guilders for being a leader of the Catholic party and a collaborator of the hated Philip II of Spain.

Johannes received a humanist education, studying Latin, Greek, theology, astronomy and astrology, and making an exact observation of the comet that appeared in 1591, which he described in one of his later treatises as a bad omen for a life full of bitterness and pain. Under Calvinist rule, the position of his family became more precarious in Deventer and eventually his parents decided to send him to Italy to continue his education.

Early career Van Heeck traveled to Milan, Parma, Ferrara, Venice, Bologna and Rome. He stayed for a while in Spoleto as a guest of Count Gelosi, with whom he maintained a connection throughout his life, and on whose estate was the villa known as the "museum deauratum" where many of his manuscripts were composed.David Freedberg, The Eye of the Lynx: Galileo, His Friends, and the Beginnings of Modern Natural History, University of Chicago Press, 2003 p.196 Here he wrote works of a moral literary character, such as his 1596 Epigrammata, as well as medical, magical and astrological topics. Among these was his Liber de Regimine Sanitatis Eorum Qui Studio Litterarum Incumbunt in which, inspired by De Vita Libri Tres ('The Threefold Life') of Marsilio Ficino, he examined the hygiene, diet and amorous habits of the literati. The second part of the work dealt with Ficino's ideas on magic. He discussed the influence of images on the spirit, and the occult virtues of certain plants, approaching his enquiry from the medical point of view rather than from that of the magician. He concluded the treatise with a list of secrets for healing common illnesses by using certain plants, and with a collection of "magic" recipes.

Following De Regimine there are four undated manuscripts dealing with plants and medicine:

De Fructibus Tractatus ('Treatise on Fruits') Tractatus de Radicibus Herbarum Diversarum ('Treatise on the Roots of Various Herbs') Tractatus de Herbis ('Treatise on Herbs') and Tractatus de Herbis et Holeribus ('Treatise on Herbs and Vegetables')

In these he described the characteristics of various fruits, herbs and vegetables, their regions of origin, the time of their flowering, ways of preparing them and their specific medicinal use. He wrote on the basis of first-hand observation, supported by ancient sources, notably Dioscorides.

With financial backing from a supportive bishop, he then studied medicine at the University of Perugia, obtaining his doctor's degree in 1601. During this period, his writing focused on logic, theology and metaphysics. Among the more significant of his works while he studied at university were:

Homines et Alia Animalia Prodigiosa Variarum Ignotarum Regionum (Of Humans and Other Animals) (1598), a summary of astronomical knowledge De Planetarum Radiationibus in Singulis Zodiaci Signis (On the Movement of the Planets Through the Signs of the Zodiac) another treatise on astronomy with numerous diagrams drawn by himself a treatise on apoplexy a treatise on angina pectoris entitled De Syncope (On Fainting) Cura Coelestis quae Inferorum Appellatur (Heavenly Care), written for doctors and for all who 'love philosophy' Super Plinii II Historias Naturales, a commentary on Pliny's 'Natural History', extended in scope beyond the original, with the ambitious subtitle 'Liber de Mirabilibus Creaturarum Dei' (Book of the Marvels of God's Creation'). In this work, van Heeck dealt with a number of contemporary concerns of natural science, such as geocentric theory and other Copernican views, against which he argued strongly.

He practised as a doctor first in Maenza and then in Scandriglia in the province of Rieti, part of the domain of Duke Giovanni Antonio Orsini. In the course of his medical work, van Heeck became involved in a strange dispute. He treated his patients, who were mostly poor, with great zeal, using simple herbal medicines. For this reason, he came into conflict with the apothecary of Scandriglia, one Casolini Ranieri, who made his living selling medicines with exotic names, more magical than scientific. Ranieri conceived a firm hatred of the foreign doctor, whose work threatened to ruin his lucrative business. One night Ranieri positioned himself on the route where van Heeck habitually passed and attacked him while he was alone. Van Heeck fell from his horse but fended off his attacker with a sword. Still bleeding from his injuries, he was brought before the magistrate. Despite his plea of self-defence, he was imprisoned. The apothecary later died of his wounds, and van Heeck would have been left to rot in prison if he had not been released through the intervention of Prince Federico Cesi, who sent Francesco Stelluti to get him out of prison and then invited him to his house in Rome.Domenico Carutti, Breve storia dell'Accademia dei Lincei, Roma, Salviucci, 1883, p. 6. The period when Cesi, van Heeck and Stelluti lived together after van Heeck's release from prison was one of an intense exchange of ideas and the shaping of plans, which led to the idea of forming a mutual-instruction society.Stillman Drake, Essays on Galileo and the History and Philosophy of Science, University of Toronto Press, 1999 vol.1 p.131

Accademia dei Lincei This close partnership between Cesi, van Heeck and Stelluti soon led to their founding the Accademia dei Lincei, together with Anastasio de Filiis, on 17 August 1603. There is no doubt that van Heeck played a key role in the conception and organization of the academy. He was the most experienced, educated and famous member of the group, and he clearly took the lead in many of its ventures,Stillman Drake, Essays on Galileo and the History and Philosophy of Science, University of Toronto Press, 1999 vol.1 p.130 though he was the second youngest among them. Like all its members, he adopted a pseudonym ("Illuminato"), an emblem (a quarter-moon illuminated by a triangle from the sun) and the motto "A Patre luminum" ('from the father of lights'). It was van Heeck who chose as the academy's patron saint John the Baptist, the apostle of arcane visions. He also drafted its articles of association and devised its ceremonial.

Van Heeck referred to the Accademia as 'the most sagacious investigators of the secrets of nature, and dedicated to the Paracelsan disciplines' – indicating thereby that like the Swiss physician, they believed that empirical observation was essential for developing an understanding of the world, rather than reliance on established scholarly authorities.Philip Ball, Curiosity: How Science Became Interested in Everything, University of Chicago Press, 2013 p.65

There has been speculation that the connections between the Accademia's members were not confined to the intellectual sphere, and, specifically in the case of the relationship between Federico Cesi and Johannes van Heeck, that they were probably sexual in nature.Philip Ball, Curiosity: How Science Became Interested in Everything, University of Chicago Press, 2013 p.66David F Noble, A World Without Women: The Christian Clerical Culture of Western Science, Knopf Doubleday Publishing Group, 2013

Travels in Europe In the spring of 1604, Prince Cesi's father the Duke of Acquasparta was so concerned about the activities of the Accademia dei Lincei and what he considered the nefarious influence of van Heeck over his son that he denounced him to the Roman Inquisition.J. L. Heilbron, Galileo, Oxford University Press, 2012 p.175 This effectively broke the four friends up, and van Heeck was obliged to leave Rome, embarking on a tour of numerous European countries. He went first to Siena, Pisa and Florence, then to Milan and Turin, where he met Giovanni Botero at the Court of Charles Emmanuel I, Duke of Savoy. Later he crossed the Alps and went to England, Norway, France, Poland, Germany and Bohemia.

While van Heeck was travelling, Federico Cesi sent him money regularly, to buy rare books on alchemy and the natural sciences, which were then added to his collection the Accademia dei Lincei.Flavia Bruni & Andrew Pettegree, Lost Books: Reconstructing the Print World of Pre-Industrial Europe, Brill, 2016 p.388 As well as collecting books, objects and rare plants for the Accademia's collections, van Heeck was also a kind of roving ambassador, telling educated men in each city about the group's work and publicising its activities to win the sympathy of the powerful and the learned.Michel Conan, Baroque Garden Cultures: Emulation, Sublimation, Subversion, Dumbarton Oaks, vol.25 2005 p.126Stillman Drake, Essays on Galileo and the History and Philosophy of Science, University of Toronto Press, 1999 vol.1 p.132 During his travels, he was attacked by robbers and forced to swallow his membership ring of the Accademia in order to prevent it from falling into the hands of his attackers.

After several months on the road, he eventually found a place in Prague at the court of Emperor Rudolf II, an enlightened and generous man who was interested in the research of the Accademia dei Lincei. Rudolf's court was a major international centre for scholars and researchers in many fields, and he owned one of the largest cabinets of curiosities ever assembled. He had been patron to Tycho Brahe until the latter's death in 1601, and at the time of van Heeck's arrival, was still patron to Johan Kepler.

The supernova of 1604

In October 1604, a new star was seen. By night, it was the brightest star in the sky, and it was visible during the day as well for more than three weeks, before eventually dimming. Both Lodovico delle Colombe and Kepler published their accounts of the new star in 1606. Van Heeck was ready to publish before them, sending his manuscript of De Nova Stella Disputatio ('Discussion of the New Star') to Federico Cesi in Rome in January 1605.

The critical question for all three writers was whether the new phenomenon could be explained within the generally-accepted model of the universe, known as the Aristotelian model or the Ptolmaic system. This held that the stars were remote, fixed in their positions and unchanging, while movement and variance were associated with the planets, closer to the Earth. An unusual event in the sky might take place close to the earth, and could therefore be explained within the standard cosmological model. However, if it took place beyond the planets, this indicated that the stars, contrary to what was commonly believed, could not be fixed in a 'firmament'. Astronomers (still working with the unaided naked eye at this time) took measurements of parallax to determine whether an object was near the earth or far away from it.