Mechanics and Mental Change

Realistic human rationality departs from ideal theories of rationality and meaning developed in epistemology and economics because in human life deliberation takes time and effort, ignorance and inconsistency do not deter action, and learning takes time and slows with time. This paper examines some theories of mental change with an eye to assessing their adequacy for characterizing realistic limits on change and uses a simple kind of reasoning system from artificial intelligence to illustrate how mechanical concepts, including mental inertia, force, work, and constitutional elasticity, provide a new language and formal framework for analyzing and specifying limits on cognitive systems. 1 Vive la Résistance The ideal actors on the stage of human imagination exhibit courageousness, decisiveness, integrity, generosity, an ability to think clearly and rapidly as they act, and an ability to change direction instantly should danger or opportunity warrant. We admire heroes and heroines and tell their stories partly to celebrate their attainment of these qualities, for many people exhibit courageousness, decisiveness, integrity, generosity, and clear thinking in small matters, and so appreciate the joy they imagine the hero and heroine must feel in larger matters. But an ability to change direction instantly? The size and profitability of the self-help section of almost any bookstore attests to the trouble most people have in changing their J. Doyle ( ) Department of Computer Science, North Carolina State University, Raleigh, NC, USA e-mail: Jon [email protected] B.-O. Küppers et al. (eds.), Evolution of Semantic Systems, DOI 10.1007/978-3-642-34997-3 7, © Springer-Verlag Berlin Heidelberg 2013 127