Jansenism

Jansenism belongs to a family of perfectionist teachings that occur regularly throughout Church history: Pharisaism, Pelagianism, Puritanism, probabilism, legalism, quietism, rigorism, rubricism, "super-spirituality," etc. It is easy to persuade good Christians that they must be "perfect as the Father is perfect" (Mt 5:48).

For St. Ignatius, these are "temptations of the Second Week." Cf. Choosing the right good.

Perfectionism breeds depression. "It doesn't have to be perfect to be good."

Five Jansenist teachings condemned by the Pope:

The condemned teaching	The true teaching
There are some commands of God which just men cannot keep, no matter how hard they wish and strive.
It is impossible for fallen man to resist sovereign grace.
It is possible for human beings who lack free will to merit.
The Semipelagians were correct to teach that prevenient grace was necessary for all interior acts, including for faith, but were incorrect to teach that fallen man is free to accept or resist prevenient grace.
It is Semipelagian to say that Christ died for all.