Hylomorphic virtue: cosmology,embryology, and moral development in Aristotle

Aristotle is traditionally read as dividing animal souls into three parts (nutritive, perceptive, and thinking), while dividing human souls into four parts (a rational part, with theoretical and practical subparts, and non-rational part, with nutritive and desiderative subparts). But careful reading of Nicomachean Ethics 1.13 suggests that he divides the human soul into three parts – the nutritive, the theoretical, and the “practical” – but allows that the “practical” part is sometimes divided, as in akratic and other non-virtuous agents. In a fully virtuous agent, practical reason is the proper form of – and so in the hylomorphic sense one with – the desiring part of soul. It is thus contingent how many parts a given soul has, three being the norm, but four being common. Reading Aristotle this way is supported by appeal to his cosmology, where the superlunary world provides the unitary norm, and his embryology, where male offspring are the norm (in which menstrual fluid is fully mastered by the male principle) but female offspring commonly occur when the menstrual fluid (analogous to desire) is only partially mastered by the male principle (analogous to practical reason).     

Searching from the top down: Ageing and attentional guidance during singleton detection

Previous investigations of adult age differences in visual search suggest that an age-related decline may exist in attentional processes dependent on the observer's knowledge of task-relevant features (top-down processing). The present experiments were conducted to examine age-related changes in top-down attentional guidance during a highly efficient form of search, singleton detection. In Experiment 1 reaction times to detect targets were lower when target features were constant (feature condition) than when target features were allowed to vary between trials (mixed condition), and this reaction time benefit was similar for younger and older adults. Experiments 2 and 3 investigated possible interactions between top-down and bottom-up (stimulus-driven) processes. Experiment 2 demonstrated that search times for both age groups could be improved when targets varied on an additional feature from distractors (double-feature condition) but only when top-down control was available (feature search). In Experiment 3, the availability of top-down guidance enabled both younger and older adults to override the distracting effects of a noninformative spatial location cue. These findings indicate that top-down attentional control mechanisms interact with bottom-up processes to guide search for targets, and that in the context of singleton detection these mechanisms of top-down control are preserved for older adults.     

The effect of the availability of a dynamic model on the acquisition of a complex cyclical action

This study examines the effect of the availability of a dynamic model on the acquisition of a complex cyclical action: slalom-type ski movements on a ski-simulator. A two-condition design was used, with N = 20 subjects per condition. In the experimental condition subjects had, during training trials, the benefit of the availability of a dynamic (video) model of an expert performer, while subjects in the control condition were left entirely to “discovery learning”. The dependent variables were the amplitude, frequency and fluency of the movement of the ski-simulator platform on which subjects were required to stand in operating the simulator. Movement characteristics of the platform were recorded by means of a microcomputer (Apple II+) coupled to a Selcom 403 camera (SELSPOT system). Subjects having the benefit of a dynamic model during training were shown, at the end of the five-day training period, to produce more fluent movements (of the platform) and to show greater consistency of fluency and of tempo than subjects left entirely to discovery learning. The results are discussed in the context of theories of perception and of motor learning.