Order of the Phoenix (fictional organisation) Order of the Phoenix (fictional organisation) The Order of the Phoenix is a secret organisation in the "Harry Potter" series of fiction books written by J. K. Rowling. Founded by Albus Dumbledore to fight Lord Voldemort and his followers, the Death Eaters, the Order lends its name to the fifth book of the series, "Harry Potter and the Order of the Phoenix". Before the Harry Potter series starts – when the character Lord Voldemort declared war on the wizarding world – Albus Dumbledore, headmaster of Hogwarts School of Witchcraft and Wizardry and an upstanding and powerful citizen of the wizarding
What Is Mathematics? Expectations" by Charles Dickens. According to Constance Reid, Courant finalized the title after a conversation with Thomas Mann. What Is Mathematics? What Is Mathematics? is a mathematics book written by Richard Courant and Herbert Robbins, published in England by Oxford University Press. It is an introduction to mathematics, intended both for the mathematics student and for the general public. First published in 1941, it discusses number theory, geometry, topology and calculus. A second edition was published in 1996 with an additional chapter on recent progress in mathematics, written by Ian Stewart. The book was based on Courant's course material. Although