The course examines the place and role of the sense of vision in Medieval and Renaissance culture. On the one hand, it emphasizes the science of optics, and on the other hand the utilization of visual means in order to shape and transmit knowledge. Special attention is given to medieval Latin thinkers such as : Hugh of St. Victor, Albertus Magnus, Thomas Aquinas, Robert Grosseteste, Roger Bacon, Witelo, and John Pecham, and to the cultural context of the medieval university, Gothic art and medieval literature (Roman de la rose and Dante's Divine Comedy). The second part of the course is dedicated to the turn of the 15th century and to the theory of artificial perspective. It focuses on the intellectual figures of the humanist Leon Battista Alberti and the theologian Nicholas Cusanus. Reading their main treatises enables a re-examination of the religious and intellectual crisis of the 16th century in the context of visual culture: from Thomas More's Utopia to the literature of alchemical emblems in the court of Rudolf II.