“the most certain sciences are like things lit up by the sun so that they may be seen. But it is God who gives the light. Reason is in our minds as sight in our eyes, and the eyes of the mind are the senses of the soul. Now, however pure it be, bodily sense cannot see any visible thing without the light of the sun. Hence, however perfect be the human mind, it cannot by reasoning know any truth without the light of God, which belongs to the aid of grace.”