Socrates wrote nothing; Plato's accounts of Socrates helped to establish western politics, ethics, and metaphysics. Both have played crucial and dramatically changing roles in western culture. In the last two centuries, the triumph of democracy has led many to side with the Athenians against a Socrates whom they were right to kill. Meanwhile the Cold War gave us polar images of Plato as both a dangerous totalitarian and an escapist intellectual. And visions of Plato have proliferated at the heart of (...) postmodern critiques of the very idea of metaphysics and politics. Plato's Progeny begins with an account of modern responses to the trial of Socrates and the controversial question of Socrates' relation to Plato. At its centre are two chapters exploring the idea of Platonic origins in and for philosophy, and of Platonic foundations for philosophical politics. Exploring unfamiliar as well as familiar invocations of Plato, Melissa Lane argues that twentieth-century ideological battles have obscured the importance of Socratic individualism, the nature of Platonic ethics, and the value of Platonic politics. Succinct and clearly written, this is an ideal guide for everyone interested in the way philosophers are still writing footnotes to Plato. (shrink)

Computational models of learning provide an alternative technique for identifying the number and type of chunks used by a subject in a specific task. Results from applying CHREST to chess expertise support the theoretical framework of Cowan and a limit in visual short-term memory capacity of 3–4 looms. An application to learning from diagrams illustrates different identifiable forms of chunk.

Pioneering work in the 1940s and 1950s suggested that the concept of chunking might be important in many processes of perception, learning and cognition in humans and animals. We summarize here the major sources of evidence for chunking mechanisms, and consider how such mechanisms have been implemented in computational models of the learning process. We distinguish two forms of chunking: the first deliberate, under strategic control, and goal-oriented; the second automatic, continuous, and linked to perceptual processes. Recent work with discrimination-network (...) computational models of long- and short-term memory (EPAM/CHREST) has produced a diverse range of applications of perceptual chunking. We focus on recent successes in verbal learning, expert memory, language acquisition and learning multiple representations, to illustrate the implementation and use of chunking mechanisms within contemporary models of human learning. (shrink)

This study is concerned with processes for discovering new theories in science. It considers a computational approach to scientific discovery, as applied to the discovery of theories in cognitive science. The approach combines two ideas. First, a process-based scientific theory can be represented as a computer program. Second, an evolutionary computational method, genetic programming, allows computer programs to be improved through a process of computational trialand-error. Putting these two ideas together leads to a system that can automatically generate and improve (...) scientific theories. The application of this method to the discovery of theories in cognitive science is examined. Theories are built up from primitive operators. These are contained in a theory language that defines the space of possible theories. An example of a theory generated by this method is described. These results support the idea that scientific discovery can be achieved through a heuristic search process, even for theories involving a sequence of steps. However, this computational approach to scientific discovery does not eliminate the need for human input. Human judgment is needed to make reasonable prior assumptions about the characteristics of operators used in the theory generation process, and to interpret and provide context for the computationally generated theories. (shrink)

This chapter reviews the historical evidence concerning the development of slavery in eastern Africa, the various forms found in societies on the coast and in the interior, the social and cultural consequences of enslavement, and its ultimate abolition. It then looks at the known and potential archaeological traces of the trajectories of these different systems of slavery, with particular reference to the area along the middle and lower Pangani River, Tanzania. The chapter concludes with a consideration of whether or not (...) it would be possible to discern slavery from the surviving archaeological remains alone, and the implications of this answer for future archaeological investigations of slavery elsewhere in the region. (shrink)

Leading archaeologists and historians provide new studies of slavery, slave resistance and the economic, environmental and political consequences of slave trading in Africa, from the first millennium AD through to the nineteenth century.

This chapter presents a synopsis of the historical evidence concerning the expansion of slavery and the trade in ivory during the Turco-Egyptian era in the Sudan between 1820 and 1881, and a description of the results of recent and very preliminary archaeological investigations at three sites associated with this trade around the town of Rumbek in Lakes State, South Sudan. The chapter begins with a brief review of the establishment of Ottoman rule in Egypt, before moving on to consider the (...) broader geopolitical forces that gave rise to the decision by the Egyptian Khedive, Mehmed Ali, to invade Sinnar, Kordofan and adjacent areas of northern Sudan. It then discusses the economic consequences and legal changes following the establishment of Turco-Egyptian rule that helped create the conditions for the expansion of slaving expeditions into southern Sudan and the establishment of a series of fortified camps or zaribas in these areas. (shrink)

We discuss the relation of the Theory of Event Coding (TEC) to a computational model of expert perception, CHREST, based on the chunking theory. TEC's status as a verbal theory leaves several questions unanswerable, such as the precise nature of internal representations used, or the degree of learning required to obtain a particular level of competence: CHREST may help answer such questions.