Lars, I added the word 'women' to the subject line because I wanted to mention a debate in 1958 that was both humorous and enlightening: "The ontological status of women and abstract entities", http://jfsowa.com/ontology/church.htm In 1947, Nelson Goodman and Willard Van Orman Quine published an article on "Steps toward a constructive nominalism", which systematically avoided abstract entities. In 1951, Alonzo Church replied with an article on The need for abstract entities. In 1958, Church continued the debate by presenting a lecture at Harvard (church.htm is an excerpt). That article explains the issues in my recent notes in this thread. I don't know whether it convinced Quine about the importance of abstract entities. But he eventually admitted that abstract entities (sets, for example) are necessary to define mathematics, and mathematics is necessary for all branches of science and engineering. If you're not convinced by church.htm and the references it cites, there is no point in continuing this thread. JFS> Perception is more fundamental to all living things than any kind of human cognition. Lars> You are right. You are pointing into a direction of cognitive research that is very notable: The school of perception-action-research. See the works of Wolfgang Prinz, Max-Plack Institute for Cognitive- and Neuroscience in Munich, and the late theoretician Odmar Neumann, University of Bielefeld). They ingeniously researched and theorized on the most basic forms of action parameterization (called 'direct [perception-to-action] parameter specification'). It's an old neuronal system/pathway still active in humans (that was therefore studied in humans). Neumann, by the way, was my cognitive psychology teacher. JFS> I agree with that point. See my review of neuroscience and its implications for AI: "The virtual reality of the mind", http://jfsowa.com/talks/vrmind.pdf My contribution to vrmind.pdf is in the selection and summary of research by other people, whom I cite with URLs in nearly every slide. John