Somewhat in line Searle's arguments in "Minds, Brains and Programs" I would say that the key is: original intentionality. Intentionality means something like 'aboutness' or 'representation', in the way that the sentence 'Hesperus is a planet' is about Venus, or represents Venus ('Hesperus' being a name for Venus). In some sense the rings on a tree represent its age: one ring per year. In some sense the written wordforms, the mere physical shapes, 'Hesperus is a planet' represent Venus. But our minds seem to represent things in a much deeper and more fundamental way. The tree rings merely correlate with its age in years. The mere wordforms only represent because we take them to do so. The intentionality of the wordforms is derived from us, whereas the intentionality of our thought that Hesperus is a planet is not derived from anything else: it is original intentionality. I would suggest, as a crude first move, that sentience is intentionality. Searle's thought was that no matter how sophisticated a...

" I recognize that there is some not inconsiderable paradox in doubting the very idea of being able to form a thought and using thought to achieve that doubt". Well spotted! Suppose that your doubts about memory lead you this: "I cannot trust any thought, including this one". Where do you go from there? It doesn't look as though the paradoxical nature the thought undermines it in such a way that you can conclude that it is false, and proceed to trust some thoughts. It sort of leaves you with nowhere to go. I agree with Stephen. Memory is not that unreliable. It is much less reliable than we think. When we seem to remember things our brains seem to do a lot of construction and interpretation, and present to us a partly made-up image of some past even as if it were a perfectly accurate representation. This can get us into trouble. But our short-term memory is pretty good and serves its purpose. It is not hard to keep track of the thoughts involved in a short line of reasoning. It also gets a...

The idea has had a mixed reception. There are many professional philosophers of mind who are not at all sympathic to it.

I think it probably has been reasonably well established. There is a plausible article about this by Susan Daffon at www.pet-tails.com/LPMArticle.asp?ID=234 Sleeping dogs exhibit a lot of behavioural signs of dreaming: they make running motions, lick their lips and so on. They exhibit rapid-eye movement sleep. And some tests have been done that tend to indicate that what goes in their brains when they sleep is pretty similar to what goes on in ours. The best explanation for all this is that they do indeed dream. As Richard says, this doesn't constitute 'proof'. But it does give us reason to believe.

I concur with Richard. The idea of positing the subconscious was first taken seriously by Freud. It was a theoretical posit, posited to explain a large number of phenomena, including slips of the tongue, dreams and a whole variety of psychological conditions such as obsessional neurosis. Freud actually got the idea from hypnosis. Under hypnosis people perform actions without knowing their own reasons for so acting (the reasons having been put into their minds by the hypnotist). Freud's 'New Introductory Lectures' provide a very good introduction to his ideas on the topic. According to Freud, all dreams are symbolic. You just don't know how to interpret the symbolism. Freud's theories, and those of later psychoanalysts, are extremely sophisticated and address a very wide range of data. Their status, however, is very controversial amongst philosophers and psychologists.

I take it that thenature/nurture controversy is the controversy concerning how much of ourcognition is innate, rather than acquired. One thing that philosophers havetried to do is get clear about what ‘innate’ might mean in this context. ‘Innate’ is not a term that is used incontemporary biology. The first idea that pops to mind is that a trait isinnate if an only if it is present at birth. But this won’t do because prenatallearning is possible. And some apparently innate characteristics, such as facialhair, appear only after birth. Thus presence at birth is neither sufficient nornecessary for innateness. Terms like ‘genetically determined’ and ‘geneticallyspecified’ won’t do either. No trait is 100% genetically determined, since theenvironment always has a causal role to play in development. And ‘geneticallyspecified’ is just a metaphor: genes do not in any literal sense specifyphenotypic traits. (For discussion, see Richard Samuels (2004) "Innateness and CognitiveScience", Trends in Cognitive...

I concur with Amy. We suppose that the eye operation itself took place, even th0ugh the patient forgot about it afterwards. It is natural to suppose that normally, in these cases, the experience of terror takes place at a specific time during the operation. So it is natural to suppose that the experience took place and was forgotten, just as the operation itself took place and was forgotten. One unlikely alternative would be to allow for some sort of weird backward causation, whereby events that occur at one time can be undone by later events. Another, slightly less whacky, alternative would be to suppose that the properties of a person's experience at a given time are not fully determined by events that take place at that time, but rather are partly determined by their place in the overall pattern of the person's life. How do any of us know that we haven't been similarly terrified? In typical cases in which an amnesic drug is administered, the subject will remember enough about...

The intuitions about the 'water' example that philosophers focus on are, as explained above, about reference. They are also about truth. It takes a little work to connect reference and truth to meaning. One line of thought goes as follows. Suppose that Oscar lands on Twin Earth. Both Oscar and Twin Oscar point to a sample of XYZ and say 'That is water'. What Twin Oscar says is true - he is speaking Twin English and Twin English speakers standardly call XYZ 'water'. But what Oscar says is false. He thinks that the stuff in front of him is water, the same kind of stuff he was familiar with on Earth. And that is the thought he is expressing when he says 'that's water'. But if what Twin Oscar says is true and what Oscar says is false, then their words must mean something different. I concur with Deniz that non-philosophers often don't respond to the example in the way that many philosophers do - although as yet no seroious data on this have been gathered. Often they either don't share the...