John Marzillier (born 1946) is a retired psychotherapist who was described as 'a significant shaper of the profession of clinical psychology' in which he practiced for 37 years.
[9] Marzillier grew up initially in Cumbria in the north of England, where his parents established a successful business in the chemical industry after having left Germany in the 1930s.
When he was 12 the family moved to the south of England, a change that Marzillier recalls had a big effect on him, as he began commuting with his brother to the City of London School for Boys.
[10] He started off as an enthusiastic behaviourist and was involved in the founding of the BABCP,[11] but eventually became skeptical of the claimed scientific foundation for the behaviour therapy in which he had trained.
He then quickly became skeptical of aspects of his training in cognitive therapy - regarding the 'core beliefs' as typically metaphysical and moral in tone and more effectively altered by emotional relational experience than challenges to logical propositions.