I'm puzzled whenever people say things such as, "I have a high tolerance for pain." How would you ever know whether your "tolerance" for pain were actually a form of insensitivity? In other words, what's the (externally observable) difference between being able to tolerate or endure pain and simply not *feeling* pain? Maybe that guy who seems admirably tough and strong-willed actually just lacks the capacity for really powerful sensations. We talk almost as though there are two parts of a person: one part which feels the pain, and another which resists.

Compare the case of pain to the heat of spicy curries or steamy saunas: I recognize certain green curries to be just as hot/spicy as certain red curries, but I have a higher tolerance for the heat/spicyness of green curries; and I can tolerate steamy saunas better than in dry saunas even when I experience them as equally hot. I am not less sensitive to the heat of green curries or the heat of a steamy sauna, but I am not bothered by them as much as I am bothered by the heat of spicy curries or dry saunas. Why isn't pain like this -- tolerated differently in different forms, or by different people, even when the amount or degree of pain is recognized to be the same? You might think that pain just is intolerance, and that the degree of one's pain is equivalent to the degree of one's intolerance, so that finding a sauna less intolerable should be equated with finding it less painful. But since the two words, "pain" and "intolerance" are used in rather different ways, and since (as you...

Why doesn't knowledge of the obvious causal relationship between consciousness and brains destroy any ideas of an afterlife?

The fact that one thing causes another does not mean than the second could not exist without the first. Consider the case of a forest fire, for example. A carelessly flung match could be the cause, and yet (a) the fire could continue even after the match is destroyed, and (b) other things, such as a bolt of lightning, could substitute for the match as cause of the fire. Similarly, one could think (a) that brain activity causes consciousness, but consciousness can continue even after the brain is destroyed, or (b) that things other than brain activity, e.g. cosmic vibrations, could also cause consciousness. Without evidence to support these possibilities, they remain mere possibilities; but they do show why the causal relation you cite does not "destroy an ideas of an afterlife". If you think that an individual's consciousness is not just caused by the activity of her brain but is identical with it, then that consciousness must indeed cease when the activity of that brain ceases. But many...

Why do philosophers care about answering question on identity or consciousness?

There is one very general reason and two more specific reasons that philosophers are interested in the question of whether consciousness is identical to a particular bodily state. The general reason is this: we are interested in knowing what the most basic constituents of the world are, and how they are related. If consciousness is not identical to a bodily state, then wewant to know what sort of thing it is and how it seems to be able tointeract with the body. But if consciousness is identical to a particular pattern of brain waves, for example, then we are justified in thinking that mental states are not something different than physical states and consciousness can be understood through the study of the brain. In short, we want to clarify different categories of existence, eliminating the confusions that result from thinking that there are two (or more) things when there is just one, or thinking that that there is just one thing when there are actually two (or more). A more...

I was reading Stanford Encyclopedia's article on consciousness and the problem of "what it is like" to be a bat. I believe that there is something that it is like to be a bat, but I guess there is nothing that it is like to be a bacterium, an amoeba or even a worm or a flea. What do you think an organism has to have so that there is something that it is like to be it? Where's the divide between fleas and bats?

I think that an organism must be conscious in order for there to be something that it is like to be that organism. This may seem like an obvious truth, but some people believe that there is something it is like to be asleep even though we are not conscious when sleeping, and some people believe that there is something it is like to have unconscious desires. If you believe either of these things, then you may well believe that there is something it is like to be an animal without consciousness. But I have trouble understanding the phrase “what it is like” to be a bat without assuming (at least some sort of) consciousness on the bat’s part. To decide whether a particular animal is conscious at a particular time, I would want to know whether it is engaged in certain sorts of information tracking. To be conscious is to be attentive in some way and being attentive, I suggest, requires one to track a given object or event across time – despite various changes in its appearance or surroundings. (A strong...