Date: 1159

"What is more remarkable, every one of us carries in his heart a book of knowledge, opened by the exercise of reason."

— John of Salisbury (c. 1115-1180)

Date: 1159

"In this [book of reason] are portrayed not only the forms of all visible things and nature in general; the invisible things of the Fabricator of all things are also written down by the very hand of God."

— John of Salisbury (c. 1115-1180)

Date: 1257

"Accordingly, there are two books, one written within, and that is [inscribed by] God's eternal Art and Wisdom; the other written without, and that is the perceptible world"

— St. Bonaventure [born Giovanni di Fidanza] (1217-1274)

Date: 1257

"Now, the woman [Eve], hearing in the external way the serpent's suggestion, failed to read the internal book that was open and quite legible to the right judgment of reason."

— St. Bonaventure [born Giovanni di Fidanza] (1217-1274)

Date: 1257

"Consequently, while original sin is a disease infecting both elements, the personal and the physical - the personal through the will and the physical through the flesh - the stain of original sin is blotted out in the soul, while on the other hand the infection and its consequences remain in the...

— St. Bonaventure [born Giovanni di Fidanza] (1217-1274)

Date: 1273

"But the human intellect, which is the lowest in the order of intelligence and most remote from the perfection of the Divine intellect, is in potentiality with regard to things intelligible, and is at first 'like a clean tablet on which nothing is written,' as the Philosopher says (De Anima iii, ...

— St. Thomas Aquinas (1225-1274)

Date: 1464

"The mind, to be sure, is like an intellectual book, which sees in itself, and for all, the intention of the author."

— Nicholas of Cusa (1401-1464)

Date: 1530

"Paucis libris vir sapiens contentus est, et quanto sapientior, tanto pauciorum codicum est indigus. Egregie autem eruditus in scrinio pectoris libriariam circunfert."

— Mair [Major], John (1467-1550)

Date: 1536

"If the Gentiles by nature have law righteousness engraved upon their minds, we surely cannot say they are utterly blind as to the conduct of life. There is nothing more common than for a man to be sufficiently instructed in a right standard of conduct by natural law (of which the apostle is here...

— Calvin, John (1509-1564)

Date: 1536

"that inward law, which we have ... described as written, even engraved, upon the hearts of all, in a sense asserts the very same things that are to be learned from the two Tables."

— Calvin, John (1509-1564)