Whether it is necessary to have contrition for each mortal sin?

Objections

Objection 1 : It would seem that it is not necessary to have contrition for each mortal sin. For the movement of contrition in justification is instantaneous: whereas a man cannot think of every mortal sin in an instant. Therefore it is not necessary to have contrition for each mortal sin.
Objection 2 : Further, contrition should be for sins, inasmuch as they turn us away from God, because we need not be contrite for turning to creatures without turning away from God. Now all mortal sins agree in turning us away from God. Therefore one contrition for all is sufficient.
Objection 3 : Further, mortal sins have more in common with one another, than actual and original sin. Now one Baptism blots out all sins both actual and original. Therefore one general contrition blots out all mortal sins.