Whether sloth is a mortal sin?

❌ Objection 1 : It would seem that sloth is not a mortal sin. For every mortal sin is contrary to a precept of the Divine Law. But sloth seems contrary to no precept, as one may see by going through the precepts of the Decalogue. Therefore sloth is not a mortal sin.

❌ Objection 2 : Further, in the same genus, a sin of deed is no less grievous than a sin of thought. Now it is not a mortal sin to refrain in deed from some spiritual good which leads to God, else it would be a mortal sin not to observe the counsels. Therefore it is not a mortal sin to refrain in thought from such like spiritual works. Therefore sloth is not a mortal sin.

❌ Objection 3 : Further, no mortal sin is to be found in a perfect man. But sloth is to be found in a perfect man: for Cassian says (De Instit. Caenob. x, l) that "sloth is well known to the solitary, and is a most vexatious and persistent foe to the hermit." Therefore sloth is not always a mortal sin.