Summa Theologica

By Thomas Aquinas

OF THE SIN OF BLASPHEMY, IN GENERAL (FOUR ARTICLES)

We must now consider the sin of blasphemy, which is opposed to the confession of faith; and (1) blasphemy in general, (2) that blasphemy which is called the sin against the Holy Ghost.

Under the first head there are four points of inquiry:

(1) Whether blasphemy is opposed to the confession of faith?

(2) Whether blasphemy is always a mortal sin?

(3) Whether blasphemy is the most grievous sin?

(4) Whether blasphemy is in the damned?