**Michael Stifel** was a German mathematician who invented logarithms independently of Napier using a totally different approach.

- The versions Styfel, Styffel, Stieffell, Stieffel are all used, as is the Latin version of his name Stifelius.
- However Stifel did not conform correctly to the Catholic faith when he became unhappy with taking money from the poor and he began to absolve poor people of their sins without taking indulgence money.
- Stifel also began, around 1520, to attempt to use methods of numerology to deduce hidden religious meanings from names particularly using the numbers which appear in the book of Revelation and in the Book of Daniel (he identified Pope Leo X with the Antichrist; we say more below about how numbers led him to this).
- Fearing for his life, Stifel fled from the monastery at Esslingen in 1522.
- Stifel published Von der christförmingen Lehre Luthers ein überaus schön künstlich Lied samt seiner Nebenauslegung Ⓣ(An extremely beautiful artful song about Luther's teaching shaped by Christ including its explanation) (1522).
- However, the castle he had escaped to at Kronberg in the Taunus Mountains was besieged by von Sickingen's enemies in October 1522 and Stifel had to flee again.
- Stifel lived in Luther's own house for a while and the two became close friends; also at this time he became friendly with Philipp Melanchthon, the Professor of Greek in Wittenberg and one of Luther's first supporters.
- In 1523 Luther obtained a position for Stifel as a pastor but anti-Lutheran pressure forced him out of this and a number of other positions, in particular one in Mansfeld and one in Upper Austria.
- Luther then set Stifel up in a parish at Annaburg travelling there with him in October of that year.
- Stifel settled down well in Annaburg.
- Luther was delighted with his staunch supporter and there was a lighter side to life too; in the summer of 1531 Luther wrote to Stifel that he, along with many cherry-loving boys, will soon visit Stifel's cherry garden.
- However, Stifel now had the time and peace to return to his earlier ways of using numerology to deduce hidden meanings.
- However, Stifel was not to be put off and many members of his congregation sold all their possessions, gave up their jobs, and waited in church for the end of the world.
- When Stifel's prediction failed he was arrested, put in jail and dismissed as a pastor at his church.
- Luther was quick to forgive his faithful follower and, with Melanchthon's assistance, secured Stifel's release from prison.
- This episode seemed to cure Stifel of his desire to use numerology to make religious predictions (at least he stopped making them public) and he began to turn his very considerable abilities towards mathematics.
- By 1535 Stifel had earned another chance to be given a parish and he went to a parish in Holzdorf, close to Annaburg and only about 35 km from Wittenberg; he remained there for 12 years.
- Stifel was forced to flee from his parish again.
- This time Stifel went to Prussia living in Memel in 1549 and Eichholz in the following year.
- By 1559 Stifel's name appears in the register University of Jena as a University Master and priest.
- Stifel's research was on arithmetic and algebra but before we examine his contributions to these areas we should say a little about the numerology that he practised before becoming a serious research mathematician.
- Let us turn now to the innovations which appear in Stifel's Arithmetica integra Ⓣ(Integral arithmetic) (1544), a work which he dedicated to Philipp Melanchthon.
- Stifel said these numbers, which he called "absurd" of "fictitious", arise when real numbers are subtracted from nothing.
- Also in Arithmetica integra, Stifel begins to present for the first time the idea of an exponent.
- Stifel wrote Arithmetica integra in Latin but his next publication Deutsche arithmetica (1545) was written in German and was clearly designed to make algebra more widely understandable to a wide range of people.
- In 1553 Stifel brought out a new edition of Rudolff's Coss, but he added more material in the form of notes and comments at the end of each chapter that he more than doubled the length of the original text.
- One of the advances in Stifel's notes is an early attempt to use negative numbers to reduce the solution of a quadratic equation to a single case.
- Another of Stifel's advances in this text was to introduce the notation A,AA,AAA,AAAAA, AA, AAA, AAAAA,AA,AAA,AAAA, ...
- Although he is producing a new edition of Rudolff's Coss, Stifel uses his own notation for roots.
- If we use ζ for Stifel's symbol for the square of the unknown, then he writes √ζ for the square root that Rudolff wrote √.
- We stress here, not that Stifel is introducing a particularly wonderful notation, but that he is so concerned with good notation.

Born 1487, Esslingen, Germany. Died 19 April 1567, Jena, Germany.

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Origin Germany, Special Numbers And Numerals

**O’Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive