Hmmm... did you submit your question via the new iPhone app by any chance? I ask because some philosophers have recently argued that the way that we use certain tools, like iPhones for example, extends our cognitive processing, and thus the mind, out into the world. Is there really a difference between the memories we store in our brains and the "memories" we store in external devices? When someone on the street asks you whether you know the time, you might answer affirmatively even though you have to consult your watch (or your phone) to tell them what time it is. You know the time in the sense that it is accessible to you. Likewise for the contacts that you have committed to iPhone memory rather than biological memory.

Were someone to have a memory chip implanted in her brain, we might well accept that as part of the mind even though it is nonbiological. But why should it matter whether the chip is implanted in the brain. Couldn't it function the same way if it were outside the brain, outside the skull even? Why should the boundaries of skull and skin matter so much? So if we can imagine someone who becomes so reliant on the info she keeps stored in her iPhone, say, that it really functions for her analogously to the way that her biological memory functions, then perhaps we would want to say that her mind too extends beyond the boundaries of skull and skin, into the world.

An excellent treatement (and defense) of these issues can be found in Andy Clark's book, Natural Born Cyborgs.

A bad person is one who is inclined to act in bad ways. A mentally ill person, accordingly, can also be a bad person. We might think of a mentally ill person as someone who simply can't help doing what they do--where those who are not mentally ill can actually make real decisions. But just because I can't help doing something terrible doesn't make it not terrible when I do it.

But I doubt that the expression "mentally ill" is one that iss very clear-cut or well conceived. Plainly, there is something wrong with anyone who acts badly--just exactly what is wrong with them (whether some "mental illness" we now have a name for, or just a lousy background, or poor education in values, or ...) may be somewhat unclear to discern, aand the border between "illness" and other factors may get extremely blurry. My guess is that the more we know about the brain, the more we are going to find out that "mental illness" will be replaced in our descriptions of the world with several other options that make what is actually wrong in various cases much clearer.

There is a wealth of psychological theorizing that can help to clarify the many ways in which memory works, or fails to work. Philosophers can sometimes help to clarify the possibilities, though. On the assumption that a memory involves the retrieval of information about an event that has occurred in one's past, there are at least three different possibilities:

1. The information trace has been eliminated. This would be the case if the part of one's brain that stored the information has deteriorated to the point where it no longer contains the relevant information.

2. Your access to the information (or a certain type of access to the information) has been lost or lessened. The information is still stored, but the processes that enable that information to be recalled, or reactivated, have ceased to operate.

3. The information continues to play an active role in your thoughts and feelings, but you are no longer aware of its role.

The answer to your question will depend on what counts as a fact.

Certainly it is possible for people to observe the same state of affairs while reacting to it differently. You observe the same wallpaper as I do, but you like it while I hate it. Or we both observe the same behavior on the part of a friend, but you find it wierd while I find it normal.

On the other hand, if the likability of the wallpaper is itself a fact that you (alledgedly) observe, then you and I do disagree about the facts when I find it hateful. Likewise, if the wierdness of a friend's behavior counts as a fact.

Rather than argue over what counts as a fact, it is probably best to recognize that different people will focus on different facts (without disputing the facts that others focus on), and that different people will value the same facts in different ways (without disputing others' descriptions of what they value). This does not mean that our focus of attention or our valuation is purely subjective, or that attention and valuation are not themselves matters for rational dispute; it only means that it is often useful to distinguish between the facts that people agree on and the ways in which they approach these facts differently.

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 note) people do often say they are more or less tolerant of pain, it would not a linguistic equivalence. Still, as you suggest, if the evidence for one is equally evidence of the other then perhaps they are in fact the very same thing.

I do not think the evidence for one is the same as the evidence for the other, however. Aside from introspective reports (which constitute one kind of evidence, after all), here are some (more objective) kinds of evidence that help to distinguish insensitivity to pain from tolerance of pain:

(1) A racing heartbeat and tensed muscles (showing sensitivity to pain) together with a calm demeanor (showing tolerance of pain).

(2) A spontaneous cry or flinch (showing sensitivity to pain) together with willingness to continue painful procedure or activity (showing tolerance of pain).

(3) An ability to give nuanced reports on the character of one's pain (showing sensitivity to pain) together with lack of interest in using pain medications (showing tolerance of pain).

While (1) and (2) may suggest two parts oneself -- one responding automatically and the other more reflectively resists these automatic responses, (3) suggests an interesting, if unusual, disconnect between the feeling of pain and the awfulness of pain. You may be interested to look at a recent book by Nikola Grahek, entitled Feeling Pain and Being in Pain, that describe some carefully documented cases of pain without painfulness and painfulness without pain.