Seite - 16 - in Wiener Jahrbuch für Kunstgeschichte, Band LIX

aSSAF PINKUS16 organ.33 Neither Grosseteste nor Bacon, how- ever, had aimed at disqualifying the extramis- sion theory, but rather at synthesizing it with the intromission theory, assimilating Aristote- lian thinking into an already well-established Platonic framework and emphasizing that intromission alone is incomplete. For exam- ple, in De iride Grosseteste states: Nor is it to be thought that the emission of visual rays [from the eye] is only imagined and without reality […]. But it should be understood that the visual species [issuing from the eye] is a substance, shining and radiating like the sun, the radiation of which, when coupled with radiation from the exterior shining body, entirely completes vision. Where- fore natural philosophers, treating that which is natural to vision (and passive), assert that vision is produced by intromission. However, math- ematicians and physicists, whose concern is with those things that are above nature, treating that which is above the nature of vision (and active), maintain that vision is produced by extramis- sion […]. Therefore, true perspective is concerned with rays emitted [by the eye].34 And elsewhere, in his commentaries on posterior analytics: For the visual ray is light passing out from the lumi- nous visual spirit to the obstacle, because vision is not completed solely in the reception of the sen- sible form without matter, but is completed in the reception just mentioned and in the radiant energy going forth from the eye.35 As observed by David C. Lindberg, Grosseteste appears to have felt that he could reconcile all theories of vision, perceiving it as both active and passive, and he therefore combined extramission and intromission into a single theory.36 Grosseteste’s simplistic synthesis was later to be articulated much more elaborately and pronouncedly by Bacon.37 For the latter, the eye was perceived as altered by an external agent operating on the passive senses, receiving the species of the thing seen, while, at the same time, sight is also the channel for a radiant power of vision, exerting its own species in the medium as far as the vis- ible object. The eye can thus act and be acted upon. This dual nature of the gaze claimed by late medieval thinkers, I believe, is sophisticatedly articulated in the Arena frescos. As discussed above, Giotto operates two main temptations for the eye: spectacle and voyeurism. While several of the scenes invite participation by pushing the fictional world forward to the first plain of the fresco toward the real world of the viewer, oth- ers push it back, away from the viewer, into an intimate sphere watched through the peephole; while the first is arrayed as a grand spectacle impressed uninterruptedly on the passive eye of the viewer, the latter requires active will and impetus by the eye, emanating from the behold- er’s curiosity and voyeuristic instinct. Giotto’s double system of architectonical composition is, in my view, not a result of evolution in his abil- ity to depict reality and space, but rather of his manipulative use and masterful understanding of what seeing is. Active seeing and voyeuristic practice are evident in various fourteenth-century cultural arenas (and in some cases even earlier, already in the thirteenth century), such as hagiographic writings and their representations,38 public and private penitential rituals that could be inspect- ed through a special aperture open to the street, medieval love narratives (in which the poet func- 33 For a survey and interpretations of Avicennas’ defense of intromission, see Camille, Before the Gaze (cit. n. 6), pp. 198–200, 204–215; D. C. Lindberg, Theories of Vision from Al-Kindi to Kepler, Chicago 1976, pp. 42–52. 34 Quoted after E. Grant (ed.), A Source Book in Medieval Science, Cambridge 1974, p. 389. 35 Quoted from A. C. Crombie, Robert Grosseteste’s Scientific Works, in: Isis 52, 1961, p. 114. 36 Lindberg, Theories of Vision (cit. n. 33), p. 101. 37 For Bacon’s synthesis, see ibidem, pp. 107–121; Biernhoff, Sight and Embodiment (cit. n. 6), pp. 74–84. 38 I refer here to the case of St. Alban and Amphibalus, which will be discussed below.