Complex sentence: The mystics known as "Quietists" insist with more or less emphasis on intellectual stillness and interior passivity as essential conditions of perfection; all have been officially proscribed as heresy in very explicit terms by the Roman Catholic Church.
Split into simpler sentences: The mystics known as "Quietists" insist, with more or less emphasis, on intellectual stillness and interior passivity as essential conditions of perfection. All have been officially proscribed as heresy in very explicit terms by the Roman Catholic Church.