34 Of these things the Church admonishes and teaches you, and touches mire, that you may not be bemired: she tells of the wounds, that you may not be wounded. But for you it is enough merely to know them: abstain from learning by experience. God thunders, and we all tremble; and they blaspheme. God lightens, and we all bow down to the earth; and they have their blasphemous sayings about the heavens. These things are written in the books of the Manichees. These things we ourselves have read, because we could not believe those who told of them: yes, for the sake of your salvation we have closely inquired into their perdition.
Source: Catechetical Lectures (New Advent)