Augustine is commonly interpreted as endorsing an extramission theory of perception in De quantitate animae. A close examination of the text shows, instead, that he is committed to its rejection. I end with some remarks about what it takes for an account of perception to be an extramission theory and with a review of the strength of evidence for attributing the extramission the- ory to Augustine on the basis of his other works.

The paper presents a preliminary estimation of the extent of dissemination of optical texts, ideas, and issues among the masters connected with the Prague faculty of arts in the late 14th and early 15th century. Investigation of this topic, so far rather neglected, is based chiefly on manuscript research. The paper brings evidence that perspectiva was taught in Prague at least since the 1370s. It suggests that investigation of Prague quodlibetal disputations (ca. 1390s – 1410s) and consideration of perspectivist authorities (...) employed in these texts can also shed some light on the issue. However, the paper is mainly devoted to the question on the mechanism of vision disputed by Bohemian arts master John of Borotín (Iohannes de Borotin, 1378 – after 1458) in the quodlibet organised by John Hus in 1411. It is suggested that the single extant exemplar of the question (preserved in the codex Prague, National Library, X.H.18) probably is Borotín’s autograph. The structure and sources of the question are analysed, with the conclusion being that Borotín proposes a compromise between intromission and extramission influenced by John Peckham’s Perspectiva communis. A critical edition of Borotín’s question is appended to the paper. / / / Please note this article is published with Brepols Publishers as a Gold Open Access article under a Creative Commons CC 4.0: BY-NC license. The article is also freely available on the website of Brepols Publishers under this same license. (shrink)

Is vision merely a state of the beholder’s sensory organ which can be explained as an immediate effect caused by external sensible objects? Or is it rather a successive process in which the observer actively scanning the surrounding environment plays a major part? These two general attitudes towards visual perception were both developed already by ancient thinkers. The former is embraced by natural philosophers (e.g., atomists and Aristotelians) and is often labelled “intromissionist”, based on their assumption that vision is an (...) outcome of the causal influence exerted by an external object upon a sensory organ receiving an entity from the object. The latter attitude to vision as a successive process is rather linked to the “extramissionist” theories of the proponents of geometrical optics (such as Euclid or Ptolemy) who suggest that an entity – a visual ray – is sent forth from the eyes to the object. The present paper focuses on the contributions to this ancient controversy proposed by some 13th-century Latin thinkers. [...]. (shrink)

Medieval Theories of Perception and the Activity of Senses in the Franciscan Context (in Czech). A book-length study (175.000 words) on Roger Bacon's, Peter Olivi's, and Peter Auriol's philosophy of perception.