"...a person who allows himself to excite his blood and take pleasure in it is unfit to receive divine grace."
"This movement of the blood is all the more dangerous because very few understand it. On the contrary, many take the sinful movement of the blood in themselves as an effect of a good influence, and follow their mistaken impulse as if it were an impulse inspired by holy truth pleasing to God."
"The blood is set into contrary motion by the passions..."
"We go not only by a narrow way; we travel by night. Constant vigilance of mind is indispensable, so as not to be drawn away by our fallen nature, and by our fathers and brothers who are drawn away by it, and so as to escape all the snares and the furious malice and humanly incomprehensible cunning and wickedness of the fallen angels."