Helisaeus Roeslin or Helisäus Röslin (17 January 1545 – 14 August 1616) was a German physician and

astrologer Astrology is a range of divinatory practices, recognized as pseudoscientific since the 18th century, that claim to discern information about human affairs and terrestrial events by studying the apparent positions of celestial objects. Di ...

who adopted a

geoheliocentric The Tychonic system (or Tychonian system) is a model of the Universe published by Tycho Brahe in the late 16th century, which combines what he saw as the mathematical benefits of the Copernican system with the philosophical and "physical" ben ...

model of the universe. He was one of five observers who concluded that the

Great Comet of 1577 The Great Comet of 1577 (official designation: C/1577 V1) is a non-periodic comet that passed close to Earth during the year 1577 AD. Having an official designation beginning with "C" classes it as a non-periodic comet, and so it is not expected t ...

was located beyond the moon. His representation of the comet, described as "an interesting, though crude, attempt," was among the earliest and was highly complex.

Life

Roeslin was born in Plieningen (now part of

Stuttgart Stuttgart (; Swabian: ; ) is the capital and largest city of the German state of Baden-Württemberg. It is located on the Neckar river in a fertile valley known as the ''Stuttgarter Kessel'' (Stuttgart Cauldron) and lies an hour from the Sw ...

). had known

Johannes Kepler Johannes Kepler (; ; 27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best known for his laws ...

since their student days and was one of his correspondents. Roeslin placed more emphasis on astrological predictions than did Kepler, and though he respected Kepler as a

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

, he rejected some of Kepler's cosmological principles, including

Copernican theory Copernican heliocentrism is the astronomical model developed by Nicolaus Copernicus and published in 1543. This model positioned the Sun at the center of the Universe, motionless, with Earth and the other planets orbiting around it in circular ...

. Kepler criticized Roeslin's predictions in his book ''De stella nova'', on the comet of 1604, and the two kept up their arguments in a series of

pamphlet A pamphlet is an unbound book (that is, without a hard cover or binding). Pamphlets may consist of a single sheet of paper that is printed on both sides and folded in half, in thirds, or in fourths, called a ''leaflet'' or it may consist of a ...

s written as

dialogue Dialogue (sometimes spelled dialog in American and British English spelling differences, American English) is a written or spoken conversational exchange between two or more people, and a literature, literary and theatrical form that depicts suc ...

s. Roeslin's 1597 book ''De opere Dei creationis'' is regarded as one of the major works in the late 16th-century controversy over the formulation of a geoheliocentric world system.

Robert Burton Robert Burton (8 February 1577 – 25 January 1640) was an English author and fellow of Oxford University, who wrote the encyclopedic tome '' The Anatomy of Melancholy''. Born in 1577 to a comfortably well-off family of the landed gentry, Bur ...

refers to Roeslin in his ''

Anatomy of Melancholy ''The Anatomy of Melancholy'' (full title: ''The Anatomy of Melancholy, What it is: With all the Kinds, Causes, Symptomes, Prognostickes, and Several Cures of it. In Three Maine Partitions with their several Sections, Members, and Subsections. Ph ...

''. Roeslin was physician-in-ordinary to the

count palatine A count palatine (Latin ''comes palatinus''), also count of the palace or palsgrave (from German ''Pfalzgraf''), was originally an official attached to a royal or imperial palace or household and later a nobleman of a rank above that of an ord ...

of Veldenz and the count of

Hanau-Lichtenberg The County of Hanau-Lichtenberg was a territory in the Holy Roman Empire. It emerged between 1456 and 1480 from a part of the County of Hanau and one half of the Barony of Lichtenberg. Following the extinction of the counts of Hanau-Lichtenberg in ...

in Buchsweiler in

Alsace Alsace (, ; ; Low Alemannic German/ gsw-FR, Elsàss ; german: Elsass ; la, Alsatia) is a cultural region and a territorial collectivity in eastern France, on the west bank of the upper Rhine next to Germany and Switzerland. In 2020, it had ...

. He made a prediction that the world would end in 1654 based on the appearance of a new star in 1572.

James Randi James Randi (born Randall James Hamilton Zwinge; August 7, 1928 – October 20, 2020) was a Canadian-American stage magician, author and scientific skeptic who extensively challenged paranormal and pseudoscientific claims. Rodrigues 2010 ...

, ''The Mask of Nostradamus'' Page 240. After Roeslin's death at Buchsweiler in 1616, his unpublished astrology, theology and

kabbalistic Kabbalah ( he, קַבָּלָה ''Qabbālā'', literally "reception, tradition") is an esoteric method, discipline and Jewish theology, school of thought in Jewish mysticism. A traditional Kabbalist is called a Mekubbal ( ''Məqūbbāl'' "rece ...

work merged into the manuscript collection of

Karl Widemann Karl Widemann or Carl Widemann or Carolus Widemann, was a German author, physician and collector of manuscripts, from Augsburg, and secretary of the English alchemist Edward Kelley, at the court of Emperor Rudolph II. Life Between 1587 and 1588, Wi ...

Life

References

Further reading