Giuseppe Veltri The Deceit of the Senses: Sight and the Mirror According to Pyrrho, as is transmitted by Aristocles via Eusebius of Caesarea, knowl- edge acquired through the senses is neither true nor false: “Now he says that Pyrrho shows that objects are equally indifferent and unfathomable and undeterminable because neither our senses nor our judgements are true or false.”1 If our senses and therefore our judgments do not fulfil the criteria of the Aristotelian principle of con- tradiction, being neither true nor false, they are either equipollent or insufficient for perception. The suspension of judgment is not only logical but also necessary. According to the Pyrrhonian Sextus Empiricus, the main argument for necessary invalidation of knowledge is “disagreement”2 because of the difference of the senses,3 for it is obvious to him that senses differ from one another. He also quotes some exam- ples of discrepancies in perception. Sextus does not question the fact that an object could show the quality of what it is appears to be (“it is possible to say what they appear to be like on any given occasion”).4 However, we are not seeking the percep- tion of the object in its appearance in a particular moment and in a particular space, but the perception according to its real nature. For then the object does not “natu- rally” have any qualities. Each of the phenomena perceived by the senses seems to be a complex: the apple, for example, seems smooth, odorous, sweet, and yellow. However, it is not clear whether it really possesses these qualities, whether it has but one quality that appears varied owing to the varying structure of the sense organs, or whether it has more qualities than are actually apparent to our senses.5 Besides the elusive impact of objects on our senses, there are also the illusions that can be provoked by them, as mentioned by Sextus in a peculiar point of the Out- lines, often cited by modern scholars, in his reference to painting: “paintings seem to sight to have recesses and projections, but not to touch.”6 Recesses and projections are a known element of geography that painters often imitate in their works; they deceive the ocular senses but not the sense of touch.7 Later on, Sextus returns to 1 Eusebius, Praeparatio Evangelica, 14.18.2–4, quoted in Jula Annas and Jonathan Barnes, The Modes of Scepticism: Ancient Texts and Modern Interpretations (Cambridge: Cambridge University Press, 1985), 11. 2 See Markus Lammenranta, “The Role of Disagreement in Pyrrhonian and Cartesian Skepticism,” in Disagreement and Skepticism, ed. Diego E. Machuca (New York: Routledge, 2012), 46–65. 3 Sextus Empiricus, Outlines of Scepticism, ed. and trans. by Julia Annas and Jonathan Barnes (Cam- bridge: Cambridge University Press, 2000), 1.91–2 and following. 4 Sextus Empiricus, 1.93. 5 See Sextus Empiricus, 1.94. 6 Sextus Empiricus, 1.92; see Annas and Barnes, The Modes of Scepticism, 69–71. 7 While it is true that a painting cannot fool the sense of touch, it is not the case for bas-reliefs or impressions made on wax. Sextus does not discuss this kind of art. https://doi.org/10.1515/9783110557602-013 The Deceit of the Senses: Sight and the Mirror 521 the topic of projection and the faculty of sight, again using the example of painting and its apparent rendering of objects that appear different if seen from one angle or another: Depending on positions: the same picture when laid down appears flat, but when put at a certain angle seems to have recesses and projections. Doves’ necks appear different in colour depending on the different ways they turn them. Since, then, all apparent things are observed in some place and from some interval and in some position, and each of these produces a great deal of variation in appearances, as we have suggested, we shall be forced to arrive at suspension of judgement by these modes too.8 The condition of the object produces divergence in the impression of senses, which necessarily leads to the suspension of judgment. Sextus attaches great impor- tance only to the object which is responsible for the differences in perception. In this context, he does not attack the reliability of the eyes in their perception; rather, he stresses the divergence of the sources of the senses. Luzzatto offers very similar argumentation in his long and complex discussion of the deceitful sense of sight and the correlating debate on the mirror, also a topic of Sextus. In Luzzatto’s little history of ophthalmology,9 which follows the topic of the discoveries and fallacies of the telescope, he displays his acquaintance with ancient, medieval and modern theories of human eyesight.10 It is well known that ancient, medieval, and early modern discussions conducted on the senses mostly relied on Aristotle’s De Anima in its multifaceted interpretations, receptions, and commentaries.11 In the second book of De Anima, Aristotle discusses sense perception in general (chapters 5 and 6), devoting chapter 7 to eyesight. For Aristotle the problem is not whether perception is caused by the objects of percep- tion, but how this is achieved and where it takes place.12 It is no surprise then that both question are objects of Luzzatto’s summary of visual perception. I emphasise the word “summary,” because he does not care to report on the development of ophthal- mology but only its theories. 8 Sextus, Outlines of Scepticism 1.120–21. 9 See Waldemar Deonna, Le Symbolisme de l’Œil (Paris: Broccard, 1965). 10 On ancient and medieval theories see David C. Lindberg, Theories of Vision from Al-Kindi to Kepler (Chicago: University of Chicago Press, 1967); Gérard Simon, Le regard, l’être et l’apparence dans l’Op- tique de l’Antiquité (Paris: Edition du Seuil, 1988); Robert Nelson, Visuality Before and Beyond the Renaissance: Seeing as Others Saw (Cambridge: Cambridge University Press, 2000). On the echoes of ancient and medieval theory in poetry (Dante), see Burt Kimmelman, “Visionary Science in Purgatorio XVII and Paradiso XXX,” Comitatus 26 (1995): 53–74. 11 For the reception of the De Anima in the early modern period, see Sascha Salatowsky, De Anima. Die Rezeption der aristotelischen Psychologie im 16. und 17. Jahrhundert (Amsterdam: Grüner, 2006). 12 See Nicholas J. Wade and Michael Swanston, Visual Perception: An Introduction (New York: Psy- chology Press, 2013), 37; T.K. Johansen, Aristotle on the Sense-Organs (Cambridge: Cambridge Univer- sity Press, 1998). 522 The Deceit of the Senses: Sight and the Mirror Despite the complexity of his enumeration of varied opinions on human vision, Luzzatto’s account is very complex. He notes that the discussion on the formation of images in optical perception is often very detailed and the conclusions reached are highly divergent. He lists the different opinions on the effusion of the image from the object to the eye as well as opinions on the place where the image is formed. First, he elucidates three theories on the modalities of sight, listing them as follows: – Some of them, as Crito already singled out, considered vision to be carried out by the efflu- vium of rays extending to an object. – Others did not accept this remote ejection and considered that the rays would first match the external light and then, once consolidated together, extend as far as the object. – Furthermore, others argued against the emission of rays and rather asserted that some images and simulacra, once detached from the objects, would enter into the eyes and that they were divided into two classes: some people thought that these images were the mate- rial remains of visible bodies, detached from the objects by the virtue and effectiveness of light; others thought that they were immaterial but proper instruments for leading us to acknowledge material objects, as they were their progenitors, although these simulacra were insensitive by themselves. – There were others who considered that sight could be carried out without the intromission of simulacra or the emission of rays, but that the presence of the object was sufficient for it to be able to encounter the visual faculty.13 An exploration of the many theories concerning sight throughout the ages is a project for another book. Here I simply seek to elucidate three theories that ancient authors were divided between: the theory that rays radiate from the eyes (emission theory); the theory that images come to the eye (intromission theory);14 and the theory that claims that the problem is how the object is received by the eyes via light and is then interpreted by the mind (reception theory), of which the most important representa- tive is Aristotle.15 The emission theory was split into two explanations of the process: the first – supported by Pythagoras, Euclid (in Optics), Ptolemy, and Leon Battista Alberti (in De pictura)16 – claimed that rays directly pass from the eyes to objects; the second – which was the Platonic conception of vision – claims that the rays emitting from the eyes have to meet with the light. This explanation is also called “the mixed theory” because light has to been emitted both by the eyes and the objects. In the Timaeus, 13 Simone Luzzatto, Socrates, 96 (all translations are taken from the present volume). 14 See Wade and Swanston, Visual Perception, 36. 15 See Harold E. Henkes and Claudia Zrenner, eds., History of Ophthalmology: Sub auspiciis Acade- miae Ophthalmologicae Internationalis, Vol. 3 (Dodrecht: Kluwer Academic Publishers, 1990). 16 Leon Battista Alberti, On Painting and on Sculpture, ed. and trans. Cecil Grayson (London: Phaidon, 1972), 40–41. See Jack M. Greenstein, “On Alberti’s ‘Sign’: Vision and Composition in Quattrocento Painting,” The Art Bulletin 79, no.