Jansenists
Jansenists are followers of the religious movement of Jansenism, which occurred in the 17th and 18th centuries especially in France, the Netherlands, Belgium, and Italy. The prime initiator of the movement was the Flemish theologian Cornelius Otto Jansen (1585-1638).
His main concern was the doctrines of grace established by Martin Luther (1483-1546) and John Calvin (1509-1564). They stated that humanity is essentially good and that everyone is responsible for their own actions, and so everyone can attain salvation by living properly.[1]
This is the view of Pelagianism, a heresy of the 5th-century, which was taught by Pelagius. He was concerned with the moral standards of Christians at that time, who were justifying the sins they committed by the original sin; that humans are weak and it's not their fault. Pelagius, however, insisted that God gave humans a free will, so that they can chose between good and evil. This makes them responsible for their actions and every sin is a voluntary act violating God's laws.[2]
Jansen, however, emphasized on the original sin and the damage it has caused to humanity. According to him, humanity is corrupted and only God's grace can save it. That means that every good act requires divine grace, and a free will doesn't exist.
During the 17th and 18th centuries, the Jansenists had their differences with the Catholic Church, which eventually led to the collapse of the Jansenist movement. It survived only in Holland, as a church in Utrecht.
It's worth mentioning that Jansen was not involved in the movement itself, since he died in 1638 and his views were published in 1640.[3]
Jansenism: Cornelius Jansen (1585–1638)
[1] "Jansenism," Encyclopædia Britannica. http://www.britannica.com/topic/Jansenism
[2] "Pelagianism," Encyclopædia Britannica. http://www.britannica.com/topic/Pelagianism
[3] "Jansenism," Encyclopædia Britannica. http://www.britannica.com/topic/Jansenism