The Reality of the World and the Realism of Fiction
The question of the very widespread and disturbing phenomenon of manipulation is as evident as it is mysterious. If it is true, as Luhmann says, that the suspicion of manipulation is the “mortal sin” of the media, it is also true that this is the subject that connects the media with reality and investigates the relations between representation and the world, their effectiveness and their consequences. It is, however, also one of the most ambiguous questions in all of the thinking about the media, one that calls into question the very idea of reality its practical effects. This is because talking about manipulation makes sense only on the assumption that there is something to manipulate, a somehow independent reality that the media report in more or less faithful or more or less distorted terms. But does this reality exist and how far is it independent of the way in which the media talk about or represent it? Is non-manipulated representation possible when the medium inevitably affects the reality it represents? When can we talk of distortion and when instead can the observer be regarded as still providing a faithful “presentation” of things?
These rather knotty problems become still more complex in the case of photography. Here the ambiguity of representation (between reality and construct) is expressed in the distinction between the mirror and the picture, which has accompanied this medium from the very outset and continues to characterize its relationship with reality. It is precisely because photography shares some characteristics of both that there is confusion as to the world it presents to us and how we stand with respect to it. Like an image in the mirror, a photograph is not independent of reality. It does not produce its own objects but rather makes it possible to observe objects that are presumed to possess real existence, made accessible by photography in a way and from a perspective that would otherwise not be available. It is precisely for this reason, curiously enough, that the images we see in a mirror are not called real images (like those of a picture) in optics but virtual, meaning images devoid to some extent of autonomy. They cannot be rotated, magnified or coloured. Nothing can be done to them. The image can only be altered by altering the object. These images are virtual because they reproduce real objects. In terms of optics, this is due to the fact that the rays of light do not proceed from the images in the mirror. In other words, they do not come from behind the surface, as it appears to the viewer, and therefore the corresponding object is not to be found behind the mirror either. Behind the mirror there is nothing of what is seen, but not because the objects in question do not exist. They certainly do, otherwise they could not be seen, but they are in front rather than behind. The mirror practices no illusion or trickery on the world, only on the observer. The illusion produced by mirrors – and generating all the riddles that have made them mysterious and fascinating objects from the very beginning - does not regard the existence of the objects but their location. While they may appear to be on the other side of the mirror’s surface, they are in actual fact the objects beside (and including) the observer but seen from a different viewpoint. The mirror does not duplicate objects but the viewpoints for observation of objects (the same objects). The observer can also see the objects “from behind” – in other words, from two different viewpoints at the same time – but the objects remain what they are. The world is still univocal and made up of “real” things.
It is a very different matter with a painting or drawing, which involves the capturing of three-dimensional reality on a two-dimensional plane and hence the problem of perspective representation, of which the photograph can be seen as the most perfect development and, in a certain sense, the final outcome. Here the problem of reality is completely different, regarding not fidelity with respect to the world but the “realism” of the representation. The goal pursued in the long and complex history of perspective and its evolution from Egyptian images to Alberti’s window is to present an object in such a credible way as to give the viewer the impression of looking through a window, to achieve a representation so perfect that it is impossible to tell the images from real objects. But what is the idea of reality underlying this? What type of object does the representation address?
What the history of perspective presents is not in fact the evolution of the relationship with reality and its representation but the transformations of illusion. As the tools available became more complex and technical, it became increasingly obvious that the painting did not only represent existing thing – concrete objects and people – but also divinities and moral or metaphysical entities, then regarded as more real than the objects that can actually be perceived. The more perfect the technique, the more it can be used to produce one’s own objects, which do not necessarily correspond to anything out there in the world or the cosmos. The “realistic” image of representation, above all with the perfecting of the technique of central perspective, gradually became more independent of the reality of the world and tended to construct a reality of its own governed by its peculiar rules and points of references, and impossible to understand solely in relation to the real world and its criteria. The image is realistic because it presents objects with such fidelity that it is possible to forget the role of the observer (the painter) and be under the impression that you are dealing directly with reality. But now it is a reality that does not exist.
This is where the difference lies with respect to the mirror and this is why the images of a perspective painting are not virtual (like those of a mirror) but can be described as real also in optical terms: images that can be worked on, enlarged, altered and corrected. They are real representations of a world that does not exist and can for that very reason be constructed at will with the tools of representation. Realistic representations, like those in perspective, no longer depend on the presence and characteristics of objects in the world but construct a world of their own so realistic as to give the impression that it is real, not least because it is a world governed by rules and criteria, thus displaying a very different degree of consistency from the flexibility of fantasy and the imagination. Luhmann talks about a “fictitious reality” attached for some centuries now to the “actual reality” of our direct experience – the product of someone’s inventiveness but not therefore any less real than the immediate world attributed to nobody. While the virtual images of the mirror do not multiply the world but only the viewpoints from which it is observed, perspective images “duplicate” reality with one or many distinct fictitious realities, creating the complicated plural ontology in which we have been moving with skill and confidence for centuries.
Even though this is a world that does not exist in actual fact, it is spoken about in terms of reality because it cannot be treated arbitrarily. It is necessary to abide by precise and very rigid rules and points of reference, otherwise the impression of realism dissolves completely. First of all, it is necessary to accept – as we automatically do – the by no means immediately obvious idea of adopting the viewpoint of the author of the representation, because while it is true that perspective represents objects faithfully, this is so only for an observer at the central point of projection, the tip of the visual cone. They look distorted from all the other viewpoints. While the image of real objects “adjusts” immediately to our movements, the perspective image is always fixed and no longer corresponds to Alberti’s window onto the world when we move. The objects are distorted and the representation as a whole is no longer at all realistic. The linear perspective no longer corresponds to natural perspective in this case, but the viewer is normally unconcerned about this and spontaneously makes the adjustments that maintain the impression of reality. Suffice it to recall the fact that we do not normally perceive commonplace images (like advertising posters) as distorted when we observe them from a position other than the centre of projection, which is something we do all the time and which produces images that are anything but realistic with respect to the position occupied by the observer.
Every perspective representation presents an inevitable element of theoretical ambiguity in that it corresponds to an infinite number of possible configurations of objects. In perspective, for example, one object is represented as smaller than another because it is farther away, but it could also be a smaller object at the same distance; two convergent lines are understood as parallel lines going away from the observer, but they could simply be slanted, and so on. Perspective representation is realistic only because we tend to interpret the images of the objects not “as they appear” but rather “as we know they are”. Correct perception of the perspective image is therefore not based simply on the realism of the representation, which would presuppose that it transmits to the eye exactly the same configuration of light rays as the real object. On the contrary, it entails a considerable degree of active involvement on the part of the beholder ultimately connected with the ability to adopt a viewpoint other than his or her own in order to interpret the image addressed.
Why do we behave in this way? What type of reality are we addressing when we look at a technically perfect perspective representation? It is certainly not actual reality but rather one of the realities constructed by other observers, whose viewpoint and interpretive categories we adopt. We look at the world through the eyes of another. What we observe is not the world directly but the world as seen by another, something of which we are so well aware that we adjust our perception automatically to allow for this condition.
The interweaving of reality and fiction can indeed be detected not only in perspective but also in several other phenomena that characterize the modern era and demonstrate a new responsiveness towards the presence of various observers with their perspectives, an awareness interpreted as the “objectivization of the subjective” by Panofsky. One of the most evident cases is the novel, which has related the wholly plausible stories of normal people ever since the 18th century rather than the incredible adventures of extraordinary characters to be found in earlier forms of narrative: heroes fighting against supernatural beings, saints performing miraculous feats, trips to the moon by Astolfo and others. The novel instead talks about people like its readers and those they know: workers, maids, shopkeepers and the like. The question thus arises of why we should invest time and emotion in reading about events similar to those we encounter in everyday life and moreover involving characters that are not only not close to us but do not even exist, as we are well aware.
The characters in modern fiction are invented by the author and in no way part of actual reality, but can for this very reason populate a fictitious world with its own rules and coordinates in which each of us knows (and must know) how to move with sureness and competence. We all know that Oliver Twist and the Artful Dodger were not nobles and that Sherlock Holmes was not French even though we also know very well that do not exist and have never existed. The events related in novels are not true, but neither are they false. They constitute a “second reality” that accompanies our real world of reference and enable us to assume the viewpoint of other characters, to live the lives of others to some degree and gain experience that we then apply also in running our own. The function of fiction in modern society lies essentially in this interweaving of different realities, where worlds that do not exist also have real consequences through their capacity to affect our perception and interpretation of “actual reality”: we all fall in love, have hopes, make plans and remember on the basis, among other things, of the models and categories encountered in fiction.
The problem of manipulation is thus dramatized and neutralized at the same time, especially in the case of photographs, which have to do both with reality and with fiction. What relationship do photographic images have with the world and what type of world do they present to us? Are they, as in the case of the mirror, images of real objects that present the world (the only existing world) to us from a different viewpoint? But the image in the mirror is a virtual image, a reflection of a real world precisely because it is not real itself, has no real substance of its own that could be worked on (and perhaps manipulated). The photograph is instead a real image in all respects, just as real as a work of fiction or a perspective representation, of which photography by no means coincidentally constitutes the most perfect form. A photograph is the impeccable embodiment of the principles of central perspective. As we have seen, however, what perspective representation presents to us is not the world but the observer’s viewpoint, not actual reality but a fictitious reality invented by someone. What about the photograph? What sense does it make to talk about manipulation when there is no claim to reproduce the world? The problem of photography is complex precisely because it interweaves the real and the virtual, the world and fiction. Or perhaps it presents the world to us in the same ways and forms as fiction. In that case, the realism of the representation is not to be measured in terms of how faithful it is to reality. This is something it can never be precisely because the photograph, like every form of perspective representation, is deeply conventional and hence in no way neutral with respect to the world. Its realism can instead lie in the capacity to present a different but not arbitrary reality and contribute in this way to the overall construction of reality in a world that is not made up only of objects but also (and above all) of observers that observe one another. A photograph shows this in the most obvious way. It is a real object but stands at the same time for an observation of the world on the part of another – in other words, for the reality of the observation (or the reality of the fiction). A photograph has a dual reference to reality: to the world and to its observers.
This has, however, been our reality for some centuries now: one made up of objects, of observers, of observation of observers and observation of how observers see the world and its objects. This is the reality in which we live, no less important and substantial than the limited and almost secondary sphere of what we see through our own eyes. The problem of manipulation must be addressed starting from here – from a complex, manifold reality steeped in fiction and observation but not therefore arbitrary and not therefore exempt from control and criticism.
Luhmann 1986, p. 63. [???] For example, the inversion of left and right in the reflected image but not top and bottom. The image seen is reversed but not upside-down. “The mirror does not represent reality, it presents reality to us.” Pirenne 1970, p. 11, n. The object of countless studies. See Damisch (1987) and Salvemini (1990). To the point where the mastery of perspective was no longer a matter of virtuosity but simply of learning a technique, a procedure that could be carried out without even thinking about it. Apart from the famous prints by Esher, the classic reference in this connection is the Ames chair. See for example Gombrich, 1960, pp. 248 ff. Segall, Campbell, Herskovits 1966, p. 95. Panofsky 1927, p.65 ed it. See Esposito 2007 for a fuller discussion of this subject. In the sense of Henrich & Iser 1983. This is demonstrated, for example, by studies on the perception of photographs and perspective images by illiterate subjects, who do not accept a whole series of techniques of representation and fail to “recognize” the objects portrayed. See Hudson 1960. Herskovits (1959, p. 56) reports the case of an African woman who, on being shown a photograph of her son, turned it round and round in an effort to give some meaning to those shades of grey on a piece of paper. It was only when individual details were pointed out that the subject became clear to her.
Bibliography
Damisch H., 1987, L’origine de la perspective, Flammarion, Paris.
Esposito E., 2007, Die Fiktion der wahrscheinlichen Realität, Suhrkamp, Frankfurt (Italian version: Probabilità improbabili. La realtà della finzione nella società moderna, Meltemi, Rome, 2008).
Gombrich E.H., 1960 (19693), Art and Illusion, Princeton University Press, Princeton (N.J.).
Herskovits M.J., 1959, ‘Art and Value’, in Redfield R., Herskovits M.J., Ekholm G.F., Aspects of Primitive Art, Museum of Primitive Art, New York, pp. 42–97.
Hudson W., 1960, ‘Pictorial Depth Perception in Sub-Cultural Groups in Africa’, The Journal of Social Psychology, 60, pp.183–208.
Panofsky E., 1927, ‘Die Perspektive als symbolische Form’, Vorträge der Bibliothek Warburg 1924-1925, Teubner, Leipzig-Berlin (Perspective as Symbolic Form, Zone Books, 1993).
Pirenne M.H., 1970, Optics, Painting and Photography, Cambridge U.P., Cambridge Salvemini F., 1990, La visione e il suo doppio. La prospettiva tra arte e scienza, Laterza, Rome-Bari.
Segall M.H., Campbell D.T., Herskovits M.J., 1966, The Influence of Culture on Visual Perception, Bobbs-Merrill, Indianapolis-New York.
The question of the very widespread and disturbing phenomenon of manipulation is as evident as it is mysterious. If it is true, as Luhmann says, that the suspicion of manipulation is the “mortal sin” of the media, it is also true that this is the subject that connects the media with reality and investigates the relations between representation and the world, their effectiveness and their consequences. It is, however, also one of the most ambiguous questions in all of the thinking about the media, one that calls into question the very idea of reality its practical effects. This is because talking about manipulation makes sense only on the assumption that there is something to manipulate, a somehow independent reality that the media report in more or less faithful or more or less distorted terms. But does this reality exist and how far is it independent of the way in which the media talk about or represent it? Is non-manipulated representation possible when the medium inevitably affects the reality it represents? When can we talk of distortion and when instead can the observer be regarded as still providing a faithful “presentation” of things?
These rather knotty problems become still more complex in the case of photography. Here the ambiguity of representation (between reality and construct) is expressed in the distinction between the mirror and the picture, which has accompanied this medium from the very outset and continues to characterize its relationship with reality. It is precisely because photography shares some characteristics of both that there is confusion as to the world it presents to us and how we stand with respect to it. Like an image in the mirror, a photograph is not independent of reality. It does not produce its own objects but rather makes it possible to observe objects that are presumed to possess real existence, made accessible by photography in a way and from a perspective that would otherwise not be available. It is precisely for this reason, curiously enough, that the images we see in a mirror are not called real images (like those of a picture) in optics but virtual, meaning images devoid to some extent of autonomy. They cannot be rotated, magnified or coloured. Nothing can be done to them. The image can only be altered by altering the object. These images are virtual because they reproduce real objects. In terms of optics, this is due to the fact that the rays of light do not proceed from the images in the mirror. In other words, they do not come from behind the surface, as it appears to the viewer, and therefore the corresponding object is not to be found behind the mirror either. Behind the mirror there is nothing of what is seen, but not because the objects in question do not exist. They certainly do, otherwise they could not be seen, but they are in front rather than behind. The mirror practices no illusion or trickery on the world, only on the observer. The illusion produced by mirrors – and generating all the riddles that have made them mysterious and fascinating objects from the very beginning - does not regard the existence of the objects but their location. While they may appear to be on the other side of the mirror’s surface, they are in actual fact the objects beside (and including) the observer but seen from a different viewpoint. The mirror does not duplicate objects but the viewpoints for observation of objects (the same objects). The observer can also see the objects “from behind” – in other words, from two different viewpoints at the same time – but the objects remain what they are. The world is still univocal and made up of “real” things.
It is a very different matter with a painting or drawing, which involves the capturing of three-dimensional reality on a two-dimensional plane and hence the problem of perspective representation, of which the photograph can be seen as the most perfect development and, in a certain sense, the final outcome. Here the problem of reality is completely different, regarding not fidelity with respect to the world but the “realism” of the representation. The goal pursued in the long and complex history of perspective and its evolution from Egyptian images to Alberti’s window is to present an object in such a credible way as to give the viewer the impression of looking through a window, to achieve a representation so perfect that it is impossible to tell the images from real objects. But what is the idea of reality underlying this? What type of object does the representation address?
What the history of perspective presents is not in fact the evolution of the relationship with reality and its representation but the transformations of illusion. As the tools available became more complex and technical, it became increasingly obvious that the painting did not only represent existing thing – concrete objects and people – but also divinities and moral or metaphysical entities, then regarded as more real than the objects that can actually be perceived. The more perfect the technique, the more it can be used to produce one’s own objects, which do not necessarily correspond to anything out there in the world or the cosmos. The “realistic” image of representation, above all with the perfecting of the technique of central perspective, gradually became more independent of the reality of the world and tended to construct a reality of its own governed by its peculiar rules and points of references, and impossible to understand solely in relation to the real world and its criteria. The image is realistic because it presents objects with such fidelity that it is possible to forget the role of the observer (the painter) and be under the impression that you are dealing directly with reality. But now it is a reality that does not exist.
This is where the difference lies with respect to the mirror and this is why the images of a perspective painting are not virtual (like those of a mirror) but can be described as real also in optical terms: images that can be worked on, enlarged, altered and corrected. They are real representations of a world that does not exist and can for that very reason be constructed at will with the tools of representation. Realistic representations, like those in perspective, no longer depend on the presence and characteristics of objects in the world but construct a world of their own so realistic as to give the impression that it is real, not least because it is a world governed by rules and criteria, thus displaying a very different degree of consistency from the flexibility of fantasy and the imagination. Luhmann talks about a “fictitious reality” attached for some centuries now to the “actual reality” of our direct experience – the product of someone’s inventiveness but not therefore any less real than the immediate world attributed to nobody. While the virtual images of the mirror do not multiply the world but only the viewpoints from which it is observed, perspective images “duplicate” reality with one or many distinct fictitious realities, creating the complicated plural ontology in which we have been moving with skill and confidence for centuries.
Even though this is a world that does not exist in actual fact, it is spoken about in terms of reality because it cannot be treated arbitrarily. It is necessary to abide by precise and very rigid rules and points of reference, otherwise the impression of realism dissolves completely. First of all, it is necessary to accept – as we automatically do – the by no means immediately obvious idea of adopting the viewpoint of the author of the representation, because while it is true that perspective represents objects faithfully, this is so only for an observer at the central point of projection, the tip of the visual cone. They look distorted from all the other viewpoints. While the image of real objects “adjusts” immediately to our movements, the perspective image is always fixed and no longer corresponds to Alberti’s window onto the world when we move. The objects are distorted and the representation as a whole is no longer at all realistic. The linear perspective no longer corresponds to natural perspective in this case, but the viewer is normally unconcerned about this and spontaneously makes the adjustments that maintain the impression of reality. Suffice it to recall the fact that we do not normally perceive commonplace images (like advertising posters) as distorted when we observe them from a position other than the centre of projection, which is something we do all the time and which produces images that are anything but realistic with respect to the position occupied by the observer.
Every perspective representation presents an inevitable element of theoretical ambiguity in that it corresponds to an infinite number of possible configurations of objects. In perspective, for example, one object is represented as smaller than another because it is farther away, but it could also be a smaller object at the same distance; two convergent lines are understood as parallel lines going away from the observer, but they could simply be slanted, and so on. Perspective representation is realistic only because we tend to interpret the images of the objects not “as they appear” but rather “as we know they are”. Correct perception of the perspective image is therefore not based simply on the realism of the representation, which would presuppose that it transmits to the eye exactly the same configuration of light rays as the real object. On the contrary, it entails a considerable degree of active involvement on the part of the beholder ultimately connected with the ability to adopt a viewpoint other than his or her own in order to interpret the image addressed.
Why do we behave in this way? What type of reality are we addressing when we look at a technically perfect perspective representation? It is certainly not actual reality but rather one of the realities constructed by other observers, whose viewpoint and interpretive categories we adopt. We look at the world through the eyes of another. What we observe is not the world directly but the world as seen by another, something of which we are so well aware that we adjust our perception automatically to allow for this condition.
The interweaving of reality and fiction can indeed be detected not only in perspective but also in several other phenomena that characterize the modern era and demonstrate a new responsiveness towards the presence of various observers with their perspectives, an awareness interpreted as the “objectivization of the subjective” by Panofsky. One of the most evident cases is the novel, which has related the wholly plausible stories of normal people ever since the 18th century rather than the incredible adventures of extraordinary characters to be found in earlier forms of narrative: heroes fighting against supernatural beings, saints performing miraculous feats, trips to the moon by Astolfo and others. The novel instead talks about people like its readers and those they know: workers, maids, shopkeepers and the like. The question thus arises of why we should invest time and emotion in reading about events similar to those we encounter in everyday life and moreover involving characters that are not only not close to us but do not even exist, as we are well aware.
The characters in modern fiction are invented by the author and in no way part of actual reality, but can for this very reason populate a fictitious world with its own rules and coordinates in which each of us knows (and must know) how to move with sureness and competence. We all know that Oliver Twist and the Artful Dodger were not nobles and that Sherlock Holmes was not French even though we also know very well that do not exist and have never existed. The events related in novels are not true, but neither are they false. They constitute a “second reality” that accompanies our real world of reference and enable us to assume the viewpoint of other characters, to live the lives of others to some degree and gain experience that we then apply also in running our own. The function of fiction in modern society lies essentially in this interweaving of different realities, where worlds that do not exist also have real consequences through their capacity to affect our perception and interpretation of “actual reality”: we all fall in love, have hopes, make plans and remember on the basis, among other things, of the models and categories encountered in fiction.
The problem of manipulation is thus dramatized and neutralized at the same time, especially in the case of photographs, which have to do both with reality and with fiction. What relationship do photographic images have with the world and what type of world do they present to us? Are they, as in the case of the mirror, images of real objects that present the world (the only existing world) to us from a different viewpoint? But the image in the mirror is a virtual image, a reflection of a real world precisely because it is not real itself, has no real substance of its own that could be worked on (and perhaps manipulated). The photograph is instead a real image in all respects, just as real as a work of fiction or a perspective representation, of which photography by no means coincidentally constitutes the most perfect form. A photograph is the impeccable embodiment of the principles of central perspective. As we have seen, however, what perspective representation presents to us is not the world but the observer’s viewpoint, not actual reality but a fictitious reality invented by someone. What about the photograph? What sense does it make to talk about manipulation when there is no claim to reproduce the world? The problem of photography is complex precisely because it interweaves the real and the virtual, the world and fiction. Or perhaps it presents the world to us in the same ways and forms as fiction. In that case, the realism of the representation is not to be measured in terms of how faithful it is to reality. This is something it can never be precisely because the photograph, like every form of perspective representation, is deeply conventional and hence in no way neutral with respect to the world. Its realism can instead lie in the capacity to present a different but not arbitrary reality and contribute in this way to the overall construction of reality in a world that is not made up only of objects but also (and above all) of observers that observe one another. A photograph shows this in the most obvious way. It is a real object but stands at the same time for an observation of the world on the part of another – in other words, for the reality of the observation (or the reality of the fiction). A photograph has a dual reference to reality: to the world and to its observers.
This has, however, been our reality for some centuries now: one made up of objects, of observers, of observation of observers and observation of how observers see the world and its objects. This is the reality in which we live, no less important and substantial than the limited and almost secondary sphere of what we see through our own eyes. The problem of manipulation must be addressed starting from here – from a complex, manifold reality steeped in fiction and observation but not therefore arbitrary and not therefore exempt from control and criticism.
Luhmann 1986, p. 63. [???] For example, the inversion of left and right in the reflected image but not top and bottom. The image seen is reversed but not upside-down. “The mirror does not represent reality, it presents reality to us.” Pirenne 1970, p. 11, n. The object of countless studies. See Damisch (1987) and Salvemini (1990). To the point where the mastery of perspective was no longer a matter of virtuosity but simply of learning a technique, a procedure that could be carried out without even thinking about it. Apart from the famous prints by Esher, the classic reference in this connection is the Ames chair. See for example Gombrich, 1960, pp. 248 ff. Segall, Campbell, Herskovits 1966, p. 95. Panofsky 1927, p.65 ed it. See Esposito 2007 for a fuller discussion of this subject. In the sense of Henrich & Iser 1983. This is demonstrated, for example, by studies on the perception of photographs and perspective images by illiterate subjects, who do not accept a whole series of techniques of representation and fail to “recognize” the objects portrayed. See Hudson 1960. Herskovits (1959, p. 56) reports the case of an African woman who, on being shown a photograph of her son, turned it round and round in an effort to give some meaning to those shades of grey on a piece of paper. It was only when individual details were pointed out that the subject became clear to her.
Bibliography
Damisch H., 1987, L’origine de la perspective, Flammarion, Paris.
Esposito E., 2007, Die Fiktion der wahrscheinlichen Realität, Suhrkamp, Frankfurt (Italian version: Probabilità improbabili. La realtà della finzione nella società moderna, Meltemi, Rome, 2008).
Gombrich E.H., 1960 (19693), Art and Illusion, Princeton University Press, Princeton (N.J.).
Herskovits M.J., 1959, ‘Art and Value’, in Redfield R., Herskovits M.J., Ekholm G.F., Aspects of Primitive Art, Museum of Primitive Art, New York, pp. 42–97.
Hudson W., 1960, ‘Pictorial Depth Perception in Sub-Cultural Groups in Africa’, The Journal of Social Psychology, 60, pp.183–208.
Panofsky E., 1927, ‘Die Perspektive als symbolische Form’, Vorträge der Bibliothek Warburg 1924-1925, Teubner, Leipzig-Berlin (Perspective as Symbolic Form, Zone Books, 1993).
Pirenne M.H., 1970, Optics, Painting and Photography, Cambridge U.P., Cambridge Salvemini F., 1990, La visione e il suo doppio. La prospettiva tra arte e scienza, Laterza, Rome-Bari.
Segall M.H., Campbell D.T., Herskovits M.J., 1966, The Influence of Culture on Visual Perception, Bobbs-Merrill, Indianapolis-New York.
