Sectarianism, according to one definition, is bigotry, discrimination or hatred arising from attaching importance to perceived differences between subdivisions within a group, such as between different denominations of a religion, class, regional or factions of a political movement.

The ideological underpinnings of attitudes and behaviours labelled as sectarian are extraordinarily varied. Members of a religious or political group may believe that their own salvation, or the success of their particular objectives, requires aggressively seeking converts from other groups; adherents of a given faction may believe that for the achievement of their own political or religious project their internal opponents must be purged.

Sometimes a group that is under economic or political pressure will kill or attack members of another group which it regards as responsible for its own decline. It may also more rigidly define the definition of "orthodox" belief within its particular group or organisation, and expel or excommunicate those who do not support this newfound clarified definition of political or religious 'orthodoxy.' In other cases, dissenters from this orthodoxy will secede from the orthodox organisation and proclaim themselves as practitioners of a reformed belief system, or holders of a perceived former orthodoxy. At other times, sectarianism may be the expression of a group's nationalistic or cultural ambitions, or exploited by demagogues.

Steven John Wilson (born 3 November 1967) is an English musician, best known as the founder, lead guitarist, singer and songwriter of progressive rock band Porcupine Tree. He is involved in many other bands and musical projects both as musician and producer (including No-Man and Blackfield) and also maintains a solo career.

Wilson is a self-taught producer, audio engineer, guitar and keyboard player, playing other instruments as and where required (including bass guitar, concert harp, hammered dulcimer and flute).

He used to split his living time between Tel Aviv and London, England, but he no longer holds a permanent residence in Tel Aviv.

Born in Kingston upon Thames, London, England (but brought up in Hemel Hempstead, Hertfordshire, England from the age of 6)^{[citation needed]}, Wilson discovered his love for music around the age of 8. It began one Christmas when his parents bought presents for each other in the form of LPs. His father and mother received Pink Floyd's The Dark Side of the Moon and Donna Summer's Love to Love You Baby, respectively. The young Steven spent much of his childhood listening to these albums in "heavy rotation", as he once commented.

Bill Bailey (born Mark Bailey; 13 January 1964) is an English comedian, musician and actor. As well as his extensive stand-up work, Bailey is well known for his role in Black Books and his appearances on Never Mind the Buzzcocks, Have I Got News for You, and QI.

Bailey was listed by the Observer as one of the 50 funniest acts in British comedy in 2003. In 2007 and again in 2010, he was voted the 7th greatest stand-up comic on Channel 4's 100 Greatest Stand-Ups.

Bailey was born in Bath, Somerset and spent most of his childhood in Keynsham, a town situated between Bath and Bristol in the West of England. His father was a medical practitioner and his mother was a hospital ward sister. His maternal grandparents lived in an annexe, built on the side of the house by his maternal grandfather who was a stonemason and builder. Two rooms at the front of the family house were for his father's surgery.

Bailey was educated at King Edward's School, an independent school in Bath where he was initially a highly academic pupil winning most of the prizes. However, at about the age of 15 years, he started to become distracted from school work when he realised the thrill of performance as a member of a school band called Behind Closed Doors, which played mostly original work. He was the only pupil at his school to study A-level music and he passed with an A grade. He also claims to have been good at sport (captain of KES 2nd XI cricket team 1982), which often surprised his teachers. He would often combine music and sport by leading the singing on the long coach trip back from away rugby fixtures. It was here that he was given his nickname Bill by his music teacher, Ian Phipps, for being able to play the song "Won't You Come Home Bill Bailey" so well on the guitar.