294 A cognitive and epistemological review interlocutor in the Yellow Emperor’s Canon of Internal Medicine, might have been Hippocrates (2–7). The intent of this article is to examine the fundamental archetypes/prototypes of pattern recognition and categori- zation in Chinese natural philosophy, and to point out that one of them is also found in the Pythagorean cult of Hygieia and in the health and safety beliefs of the Old Religion of Northern Europe. Common inheritance, convergence or transmission, this architectonic similar- ity—in any case—further supports Paul Unschuld’s view that ‘the notion of a vast dichotomy between Western and Chinese reactions to disease is completely unfounded’ (5). Conceptual Approaches This essay uses concepts from Cognitive Science, Continental Philosophy and Epistemology, and Discrete and Dynamical Systems Mathematics to deconstruct the infrastructure of Chinese medical thought, and to reveal its cognitive map and epistemic architecture. Historical suggestions that follow have the sole purpose of providing a stimulus for further discussion and research. The historical and philosophical sources are the English secondary literature by prominent Western sinologists. All Chinese terms are written in Pinyin and only Anglicized names of Chinese Classics are utilized. Romanized and Anglicized Greek words and Latin terms are in italics. The Chinese Models of Disease From the standpoint of knowledge architecture and representation, the core cognitive frame of reference in Chinese medical discourse is a combination of two key dynamical-processes pattern categorization schemas that seem to have been grafted together to form a hybrid system of thought. One emanates from ancient Chinese metaphysics that views ontogenesis (in the philosophical sense of the term) as the product of a wavering between an inhibiting and an activating force, called Yin and Yang, and symbolized by a broken (- -) and a solid (—) line, respectively. In this model, spatiotemporal events are assessed based on their dynamic state called ‘Qi’ (pronounced Ch’i), and plotted against a hierarchical and tree-like system similar to what is known as a ‘period-doubling bifurcation’ in Dynamical Systems Mathematics. For instance, at a second level of bifurca- tion, there are four possibe qualitative outcomes in a dynamic event, such as in the course of a disease: Yang-Yang, Yang-Yin, Yin-Yang and Yin-Yin peri- ods (8). According to the English secondary literature, one of the earliest references to this model is found in the I-Ching translated as the ‘Book of Changes’ or the 6 ‘Classic of Changes,’ in which 2 , or 64, topologies/ combinatorics of Yin and Yang called ‘Hexagrams’ Figure 1. The I-Ching itemizes 64 combinatorics of Yin and Yang. Source: www.theory.org/ strthrwr/retired/iching.html. (Fig. 1) are itemized and described, seemingly for the purpose of cleromancy and divination. As for the epistemological merits of using a hierachical inhibiting-activating model to conceptualize biological processes, Weiss, Qu and Garfinkel of University of California point out that it can only constitute a ‘minimal model,’ with limited abilities to directly relate its predictions to nature’s dynamical and emergent behavior, and that often biological events do not have explicit counterparts in it. Although their general assessment is not based on Chinese thought but on Alan Turing’s purely mathematical model as described in his 1952 article ‘The Chemical Basis of Morphogenesis,’ it could nonetheless be applied to the Yin-Yang model, given that these empirical notions appear as being analogous to Turing’s ‘short-range activating’ and ‘long-range inhibit- ing’ forces, and that within their contexts, both binary models seem to have the same epistemological limitations for their use of the minimum number of parameters needed to represent the dynamical nature of biological events (9). The other key categorization schema, also known as the 5-Elements/Agents or 5-Phases/Stages theory, is a non-linear syntactic (or structural) pattern recognition construct, which is known in Cognitive Science as an ‘associative multiparameter’ or a ‘Hopfield-style’ net- work. This type of congnitive organization consists of a set of essential parameters (variables/nodes) and a lattice of dependency-relationships (vector/arcs) that fully inter- link them. This architecture seems to mirror the neural correlates of Hebbian learning. In the context of Chinese ancient metaphysics, the parameters are established by a ‘five-fold’ (Unschuld) discretization of all possibilities in every ontological domain into five mutually-exclusive variables, or paradigms, traditionally called Water, Wood, Fire, Earth and Metal (Table 1). Each parameter is attributed a finite number of potential states ranging from ‘deficiency’ to ‘excess,’ where events could be