Brunelleschi was also present. Already in his first philosophical book, De docta ignorantia (1440–42), we see Cusa developing a philosophically more rigorous account of the early modern mathematization of space, one that avoids the simplifications of Alberti. In fact this account displays amazing similarities to the liturgical vision of space in the North Burgundy paintings by artists such as Jan van Eyck. Even more significant, however, is a little book that Cusa sent to the monks at the Monastery