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Limits
Minimum spatial competence | pp. 4-5 | ...the problem of minimum necessary competence. [...] . Is it not possible that hominids used their most sophisticated spatial concepts in realms other than stone knapping? It is difficult to get around this problem. Indeed, we can never logically eliminate the possibility that a two-million-year-old Euclid made crude stone tools while drawing triangles in the sand. |
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Spacial thinking
Nature of spatial thinking | p. 1 | While spatial thinking may not be the key to the evolution of human thinking, it may be a window through which we can glimpse the evolution of the hominid mind. |
Correlation ancient thinking ~ modern analysis | p. 2 | The analysis [...] is organized according to types of spatial relations. The division is one of convenience; I do not mean to suggest that hominids compartmentalized their spatial thinking in such a fashion. Topology, projective geometry, and euclidean geometry are all fields of formalized geometry and as such are at least vaguely familiar to readers. |
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Overall shape
Disregard for overall shape | p. 23f. | the knapper had to position the trimming blows in a rudimentary series in which sequential blows were spatially related to several preceding blows. This is a simple concept of order. All of these Oldowan concepts of space are simple, and, interestingly, all appear to be focused on the configuration of edges. There appear to have been no ideas about appropriate overall shape, nor any spatial concepts used solely to control overall shape. [...] Notions of overall artifact shape appear after the Oldowan. [...] The minimally trimmed bifaces from Isimila [300,000 years ago] represent the most sophisticated concepts of topological space. Here the knapper directed blows to achieve an overall shape in a very economical manner. |
p. 60 | There appears to have been little attention to the overall shape of Oldowan tools. It was the configuration of edges that was the goal of these stone knappers. [...] The hominids appear to have made no attempt to alter the overall shape of the tools, for whatever reason. Such attention to overall shape is a characteristic of succeeding technologies. | |
Appearance 1,200,000 years ago | p. 61 | Both the notion of interval and the notion of symmetry contributed to the development of the idea of the artifact as a whole. No longer did hominids focus attention only on the edge; they attempted to attain certain overall shapes. Discoids, spheroids, and bifaces all required some notion of overall design. |
Awareness of intended results | p. 62 | Like earlier hominids they had an idea of final shape, but, unlike their earlier counterparts, they had a sophisticated array of spatial concepts for conceiving and attaining the desired result. |
A landmark (1,200,000 years ago) | p. 63 | Oldowan hominids attended to the nature of the edge – probably tied to a specific task at hand – and paid no attention to the overall shape of their tools. These edges required, as we have seen, only rudimentary spatial concepts. [...] The acquisition that first takes hominid tools out of range of ape spatial concepts is the notion of overall shape, or, to put it a bit differently, some conception of the tool as a whole. While the edge-oriented technology of the Oldowan appears to have been tied to immediate tasks at hand (an ad hoc technology), the presence of tools with repeated, overall shape suggests that in these cases, an idea of the whole tool existed previously in the mind of the knapper. [...] We do not know why these 1.2-million-year-old hominids strived to attain this particular shape, but we do know some of the shape's conceptual requirements. With bifaces, the whole tool, more or less, had to be conceived ahead of time. |
Repetitive patterns | p. 64 | While the idea of artifact- or object-as-a-whole may seem painfully rudimentary, it represents a much more comprehensive organization of space than that used in the Oldowan. Simple spatial notions like order and separation had now become elements arranged into higher-level patterns. Moreover, these patterns could be repeated again and again because they existed as specific intentions. Technology could exist apart from a specific task at hand, and, indeed, had come to occupy a conceptual realm of its own. |
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External perspective
Importance of such ability | p. 38 | The ability to distinguish and coordinate independent perspectives is an important component of modern adult concepts of space. It is commonplace for us to imagine how an object or scene will appear from another perspective (we even use similar skills to measure intelligence on standard tests). It is an efficient and useful way to apprehend the world. Without this ability, the world would constantly present unfamiliar scenes. Even well-known objects would, if approached or seen from a new angle, appear different because of the inability to imagine how they would appear from the other, familiar angle. [...] projective notions [...] are important spatial notions. Awareness of independent points of view implies that an individual recognizes that both he and the object exist within a space of changing relative positions. |
Children know only their viewpoint | p. 38 | Young children do not possess this concept, and its absence yields an interesting notion of space. For example, when presented objects arranged into a scene, young children consider the relative spatial position to be permanent; that is, they assume that the left-right and front-back order that is visible from their perspective is the same for all other observers. When asked to predict the shape of a shadow on a screen, they describe the object as they see it from their own position. In other words, young children do not consider viewpoints other than their own (Piaget and Inhelder 1967). |
A landmark | p. 64 | The second constellation of spatial concepts includes euclidean and projective notions, along with a more sophisticated understanding~of the relation or whole to parts. The acquisition of this constellation appears to have hinged on a single breakthrough in spatial thinking - the invention or discovery of perspective. This projective notion was the key that allowed the extension of internal spatial frames that were anchored to specific objects into general constructions of space that organized possible as well as real positions. |
A conceptual feat | p. 64 | As we can see from the early bifaces from West Natron and Olduvai, a notion of interval was in use fairly early, but there is no evidence of general frames of reference. Intervals are, by themselves, insufficient. What is required "as well is a constant orientation, and such constant orientation is impossible without some notion of viewpoints that exist independent of that of ego. One must be able to step away from the tyranny imposed by direct perception and construct alternative views. This is quite a conceptual feat, requiring complex substitutions and restructuring of shapes. Moreover, it requires the subjugation of what one actually sees to what one thinks. |
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Symmetry
Regularity of plan | p. 33 | Neither artifact's cross section shows the symmetrical regularity occasionally seen on the Isimila bifaces. However, the plan shape of each of these artifacts is at least roughly symmetrical. I will treat the symmetry later; what is important here is that there is attention to regularity in plan, which can be directly checked, but no clear attention to cross section, which would have required imaginary perspectives. |
Relationship to natural shapes | p. 44 | Is it possible that spheroids resulted not from some spatial concept of interval but simply from the copying of a model in nature – a fruit, for example? This is a knotty problem to which I will return later in the discussion of symmetry. |
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Intentionality
Secondary trimming as indicative of intentionality | p. 3 | Much that is regular about stone tools is purely accidental. [...] Intention does not require some sophisticated image or mental template. [...] The analyses in this book concern, therefore, the patterns of trimming found on tools. Occasionally they also consider the overall shape of the artifact, but only in cases where it is clearly the result of extensive trimming. | p. 37 | Without extensive trimming it is difficult to argue for any kind of intention. | p. 39 | It is the amount of trimming that makes me cautious; the shape just might be fortuitous. | p. 41 | Moreover, neither artifact is extensively trimmed, making it hard to argue for an intentional shape. [...] The disc shape is probably fortuitous. |
Repetitive examples | p. 4 | I did try to avoid unique examples. Even though a remarkable pattern or configuration seemed, at least to me, certainly intentional, it remained just possible that it was an accident. However, if this pattern was repeated on another artifact, I decided that the possibility of its being an accident was reduced to an acceptably low level, and felt comfortable in including it in the sample. There are only two or three such unusual patterns in the study. |
Symmetry | p. 18 | For objects such as the choppers and scrapers of previous examples it is impossible to make judgments about minimal trimming because we have little idea of the knapper's intention concerning overall shape, if in fact he had one. But for artifacts with symmetry or regularity of any arbitrary kind we can make such judgments, keeping in mind that they are, in fact, judgments. |
Quick planning | p. 19 | [...] we need not envision the hominid in agonizing contemplation, but even quick, on-the-spot planning required a notion of whole and part. |
Caution | p. 32 | These examples are cautionary and I include them to emphasize the care that must be taken in determining the necessary competence of hominid stone knappers. Regularity in stone tools can be accidental, and, moreover, even extensively trimmed artifacts can be irregular. | p. 45 | The same caveats hold when one examines stone tools for parallel edges that hold when one inspects them for projective relations. It is especially hard to prove intention. |
Simple notions | p. 40 | The amount of trimming on this discoid suggests that the final shape was probably intentional. [...] At the minimum, he must have used some concept of radius or diameter, that is some notion of a constant amount of space separating all of the edges. [...] I do not mean to argue that the knapper was a geometrician and reflected upon such concepts, only that he used a simple notion of interval in his spatial repertoire. |
Insufficient evidence | p. 52f. | [...] there is nothing about the location of trimming that suggests that the shape of the original cobble was significantly altered. [...] In this case, the symmetry is in the heads of the archaeologists. |
No verbalization | p. 57 | Again I must emphasize that the knapper need not have been able to describe or to verbalize his concepts in nice mathematical terms. |
No conscious theorizing | p. 63 | Like earlier hominids they had an idea of final shape, but, unlike their earlier counterparts, they had a sophisticated array of spatial concepts for conceiving and attaining the desired result. |