Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!elroy.jpl.nasa.gov!sdd.hp.com!caen!umich!sharkey!tygra!dave From: dave@tygra.Michigan.COM (David Conrad) Newsgroups: comp.ai.philosophy Subject: Re: Direct awareness (was Re: UNIFIED MODEL FOR KNOWLEDGE REPRESENTATION? (IMPOSSIBLE Message-ID: <1991Jun19.095424.4538@tygra.Michigan.COM> Date: 19 Jun 91 09:54:24 GMT References: <8455@awdprime.UUCP> <1991Jun16.083632.1383@tygra.Michigan.COM> <1991Jun17.144356.21450@aifh.ed.ac.uk> Organization: CAT-TALK Conferencing System, Detroit, MI Lines: 64 In article <1991Jun17.144356.21450@aifh.ed.ac.uk> bhw@aifh.ed.ac.uk (Barbara H. Webb (Phd 89)) writes: >In article <1991Jun16.083632.1383@tygra.Michigan.COM> dave@tygra.Michigan.COM (David Conrad) writes: > >>Bertrand Russell has a fascinating discussion of all this in his book >>_The_Problems_of_Philosophy_. He concludes that we cannot know anything >>about objects in the world directly, but only indirectly. The only things >>we can have direct knowledge of are our sensations. Our knowledge of >>objects must always be indirect. Actually, in addition to our perceptions >>we are also directly aware of abstract concepts, which Russell terms >>'Universals'. E.g. I am aware of my sensation of seeing this keyboard >>in front of me, and touching it, and hearing the keys click, but I cannot >>be *aware* of the existance of the keyboard; I can only infer its existance. > >What is 'knowing' or 'being aware of' if it is not the process of >sensing or percieving something? If you _have_ the sensation of seeing >your keyboard, then you are aware of your keyboard (directly) rather >than aware of your sensation. What you describe solves the problem of >_how_ awareness occurs, not by finding the processes underlying it, but by >moving the entire problem back one step - the senses project the outside >world onto a video screen inside our heads and the little man inside our >head 'knows directly' what he sees there, and infers that it reflects >some real scene going on outside the head. This is not much help to a >science of cognition, because we don't how the little man manages his >'direct awareness' any more than we knew how we were aware of the world in >the first place. > This is all true, but not what I was talking about. By 'aware' I was not referring to consciousness, but to knowledge of the existence of an object. My seeing the keyboard does not necessarily mean that any keyboard exists. An example from my own experience: a friend of mine who was working in an optics lab at the University of Michigan showed me a small not-quite-round ceramic ball which had a penny sitting on top of it. I saw the penny. I reached for the penny. My fingers passed right through the penny. There was no penny there. (The inside of the 'ball' was mirrored, and the real penny which was 'causing' the image was sitting at the bottom.) I was not aware of the penny. No penny had influenced my nervous system. Indeed, no penny ever could. Some photons had hit my retina in a way which all my previous experience led me to believe meant "there's a penny," but there wasn't, at least, not where I thought there was. In a world where our own knowledge of objects is so problematic, the question "how can any two people know that they are referring to the same object," (remember, that was the original question) seems to be somewhat naive. How can *one* person be sure what object in the real world his or her thoughts refer to? My thoughts referred to "the penny on top of the ball," but there was no such referrant. So we cannot even hope to ask how *two* people can be sure they're referring to the same object. It seems obvious that there are only degrees of "thinking that the other person may be referring to the same object as me." Bertrand Russell, as I mentioned before, has a very readable and interesting discussion of perceptions, objects, Solipsism, and much more in his book _The_Problems_of_Philosophy_. David R. Conrad dave@michigan.com -- = CAT-TALK Conferencing Network, Computer Conferencing and File Archive = - 1-313-343-0800, 300/1200/2400/9600 baud, 8/N/1. New users use 'new' - = as a login id. AVAILABLE VIA PC-PURSUIT!!! (City code "MIDET") = E-MAIL Address: dave@Michigan.COM