Whether presumption is a sin?

❌ Objection 1 : It seems that presumption is not a sin. For the Apostle says: "Forgetting the things that are behind, I stretch forth [Vulg.: 'and stretching forth'] myself to those that are before." But it seems to savor of presumption that one should tend to what is above oneself. Therefore presumption is not a sin.

❌ Objection 2 : Further, the Philosopher says (Ethic. i, 7) "we should not listen to those who would persuade us to relish human things because we are men, or mortal things because we are mortal, but we should relish those that make us immortal": and (Metaph. i) "that man should pursue divine things as far as possible." Now divine and immortal things are seemingly far above man. Since then presumption consists essentially in tending to what is above oneself, it seems that presumption is something praiseworthy, rather than a sin.

❌ Objection 3 : Further, the Apostle says (2 Cor. 3:5): "Not that we are sufficient to think anything of ourselves, as of ourselves." If then presumption, by which one strives at that for which one is not sufficient, be a sin, it seems that man cannot lawfully even think of anything good: which is absurd. Therefore presumption is not a sin.