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We know for now, at least, it's impossible to go back in time scientifically.

We know for now, at least, it's impossible to go back in time scientifically. But what if you really needed to, say if you had done something really bad and had ever desperation to go back in time and correct what you did, so you don't suffer the consequences you are suffering in the present. Provided you would not cause a disaster by going back in time, and that you would only change the bad things you did, it is an interesting concept. With this context, if you could be given a drug, that would leave you asleep for the rest of your life (coma), would you do it? Read on, there's more. In this sleep, you will have a dream, which is set from just before your mistake. So essentially, it causes you to simulate the past and the rest of your life in your head. It seems real, but it isn't. My question is, would this be the same as going back in time and changing things in reality? Does reality matter more, or our interpretation of it?

First a terminological quibble. By "scientifically impossible," I take it you mean "technological infeasible," i.e., impossible given the limits of current technology. As I see it, what's scientifically possible or impossible depends only on the laws of nature, which are standardly taken to be unchanging over time (or at least over any time that humans will experience). I think the jury's still out on whether backward time-travel is scientifically impossible in this latter sense.

To your question: I think there's something self-contradictory in the idea of "correcting what you did" if that means "bringing it about that you never did what you in fact did." Either (1) you did it, or (~ 1) you never did it. I can't see how any consistent story features both (1) and (~ 1).

In that sense, then, there's no such thing as (2) "going back in time and changing things in reality" and therefore nothing that's the "same as" (2). See section 1.2 of the SEP article on time-travel.

Has philosophy learned anything from psychoanalysis?Kal

Has philosophy learned anything from psychoanalysis? Kal

The quick answer is that 'analytic' philosophy has not, but 'continental' philosophy has. Almost all the major figures in continental philosophy after Husserl engaged with psychoanalytic thinking - Heidegger, Scheler, Merleau-Ponty, Sartre, Derrida, Foucault, and the French feminist school of Irigaray, Cixous and Kristeva. So continental philosophy as a discipline tends to work with and from an awareness of psychoanalytic thinking, and this has an effect on a very wide range of issues (language, ethics, gender, mind, politics...)

Analytic philosophy has been more sceptical about the truth of the psychoanalytic model of the mind, and engaged far more with cognitive, and more recently social, psychology. It has only begun to deal with the unconscious mind through these empirical theories. There are exceptions; Richard Wollheim and Jonathan Lear have written widely on psychoanalysis, and a number of writers in ethics, e.g. Charles Taylor, Harry Frankfurt, Richard Moran, John Cottingham, David Velleman, and Edward Harcourt have argued for a psychoanalytically informed account of moral psychology and self-knowledge (as have I). But even among those sympathetic to psychoanalysis, the range of issues on which psychoanalytic thought is brought to bear has been relatively limited.

If two people share a thought influenced by their shared experiences, would this

If two people share a thought influenced by their shared experiences, would this be considered telepathy? For example, if two people see a stimulus and instantly link that stimulus to a situation experienced with the other person, does it become telepathy because they both think it at the same time, and have some time of relationship?

No. At least, not if by "telepathy," you mean what most people mean. Usually when people talk about telepathy, what they have in mind is one person's thoughts influencing another person's thoughts without usual means of influence such as speaking, telephoning, etc. What you've described is a case of "common cause." It's not a matter of one person's thoughts influencing another person's. It's a matter of a common stimulus influencing each person's thoughts.

To give a clearer example: suppose you and I are, as it happens, both watching the same TV program, though in different cities. An image of a mushroom cloud appears onscreen and we both think of Hiroshima. That's not telepathy. Nor would it be telepathy if the two of us had also once met and talked about the history of the atomic bomb.

to what extent is the definition of mental "health" conditioned by society and

to what extent is the definition of mental "health" conditioned by society and social mores? To what extent is the job of a psychotherapist grounded in and/or free from the beliefs of the society in which s/he operates?

I may be wrong, but I have a sense that your key interest is the extent to which matters of mental health are grounded in nature or in a reality that is independent of changing or contingent matters, right? I am checking in to make sure I get the question, for there is a sense in which if you are asking about whether the term 'health' is defined by society, the reply should probably be that 'health' like all terms (from 'dog' to 'mountain') in all languages is indeed defined by social conventions. But it is a further matter whether 'health' or 'mental health' refers to something that is not only a matter of social convention. If I am right about your concern, then I think we have reason to believe that there are some norms that define 'mental health' and 'mental illness' that appear to range over cultures (or that cultures hold in common) and are pretty basic, e.g. it is not mentally healthy for parents to torture their children or for pilots to deliberately crash an airplane full of passengers into the Alps killing all aboard or for persons who are otherwise healthy to wash their hands every two minutes due to no apparent reason, and so on. But apart from some basic, widespread (perhaps even "common sense") boundaries, there can be significant reasonable disagreements. To take an extreme case, Richard Dawkins contends that those who believe in God are subject to what he at least used to call "the God delusions" --as he is not a psychologist or psychotherapist, consider Sigmund Freud who contended that religious believers were subject to a pathology, namely the Oedipal complex. Many of us (including me) thinks this charge is groundless and reflects either mistaken philosophical assumptions or (using stronger language) unwarranted prejudice. So, overall, I think that while there are some basic boundaries between mental health and illness, there is a great deal to debate. On the job of psychotherapists, insofar as she or he is committed to the health of her clients (or fellow citizens) I suggest the therapist would have reason to discern when some norm is merely socially contingent versus one that is deep and not subject to social variation. Sexual orientation may be a good case in point. If a therapist is working with a client who has homosexual tendencies and yet is working in a society that deems homosexuality a mental disorder, then the therapist may indeed have a job in proposing that the current "beliefs of the society in which s/he operates" are ungrounded or contingent.

If we as professional and amateur philosophers are to accept psychology as a

If we as professional and amateur philosophers are to accept psychology as a science (see question 5362 answered by Charles Taliaferro), then what does that make psychiatry? Even if a person fits all the criteria for having a mental disorder according to principles of psychology yet he refuses treatment, why should medical or pseudo-medical psychiatrists intervene so long as that individual decides to refuse to concur with the diagnoses or more importantly refuses to to acknowledge the treatment while accepting the diagnoses? Isn't psychiatry then just a mostly futile exercise in normative ethics to the whim of the patient?

I don't think much depends here on whether psychology or psychiatry is a science. What matters is whether they are doing good or not for patients. Supposing we think they are, a commonsense criterion seems to be that even if patients do not accept the diagnosis or the treatment, things change if they are contemplating harm to themselves or others, as the jargon has it. The jargon persists and is more than jargon because it has a real role; it is a criterion. A second criterion or perhaps test might be this. Can the patients get through the day or week to their own satisfaction, or look after themselves OK? If I have a friend who never gets up, doesn't bathe, won't look me in the eye, can't work and doesn't eat, and has gone down to eighty pounds, then I feel justified in intervening, because of this second criterion, over the stated wishes of the patient. Something is wrong, and I have an obligation, or some responsibility anyway, to help, especially if I am a psychiatrist. Most people in trouble do want help, I think, even if we are too dim to find the way. "Normative" ethics means ethics which is not-metaethical. I think you may be misusing the word; what you may mean is a highly directive ethics that conflicts with the patient's own ethics. The patient too has a normative ethics - his own. And what if psychiatry is misguided or "pseudo-medical" and does harm? If that is true, then we should avoid it, of course. But is it true? It seems to me it is a bit improbable that the profession as a whole is phony. It is not monolithic enough for that, for one thing. One can always switch psychiatrists.

Do most philosophers take the Paul and Patricia Churchland's eliminative

Do most philosophers take the Paul and Patricia Churchland's eliminative materialism seriously? I'm concerned about the current state of philosophy of mind in that it seems that at least some people take seriously the suggestion that e.g. beliefs don't exist (and that they are believed in in a theoretical manner). So, again, how popular is the Churchland's eliminative materialism in contemporary philosophy of mind?

I'm not sure why you regard it as a worrisome sign about current philosophy of mind that some of its practitioners take eliminative materialism (EM) seriously. At worst, it would show that some philosophers regard EM as far more plausible than it really is, but even then I don't see how that would indict current philosophy of mind as a whole.

Anyway, you've asked an empirical question whose answer depends on (1) reliable data about the views of philosophers and (2) what you mean by "take seriously." I presume you mean something like "regard as too plausible to be dismissed without argument," which is a weaker attitude than "regard as plausible." I don't have empirical data, but my hunch is that most philosophers do take EM seriously in that sense, but probably because most philosophers don't regard any philosophical position as worthy of being dismissed literally without argument. At the same time, however, my hunch is that most philosophers regard EM as implausible.

Curiously, the PhilPapers Survey doesn't ask about attitudes toward EM, although it does ask about attitudes toward other positions in philosophy of mind. One might conclude that the survey organizers didn't regard EM as worth asking about, which might reflect the organizers' own hunch about the popularity of EM, but they do ask about several philosophical positions that garner the support of only a tiny minority (3% or so) of those surveyed. So I don't know what to conclude about the omission of EM from the list.

But far more important than the actual distribution of views about EM are the arguments for and against it. About those, see this SEP entry.

Can you choice what to belive in?

Can you choice what to belive in?

A good question. Usually we can't just choose what to believe. For example, I can't decide to believe that there's an elephant in the room with me, no matter how hard I try. That's likely because we're wired in a way that won't usually let us override the evidence of our senses. But the words "believe in" are typically applied to things that we can't check on simply by looking around—things like belief in God, or belief in the trustworthiness of a friend. (It's not that the evidence of our senses is simply irrelevant to such things, but it's seldom definitive.) In matters where the senses don't just settle things, it's a genuine question whether we can decide to believe, and my sense is that we often can.

A comparison might help. Suppose my friend has been accused of something, and he asks me to speak for him as a character witness. I can certainly decide whether I'm going to do that. The decision might be easy, but the more interesting cases are the ones where it doesn't just seem obvious what to do. There we have a real feeling of deciding. Now suppose I ask my friend about the accusation. He tells me his version of events, and if his story is true it's clear that he's innocent. I think that in cases like this we sometimes have the sense of deciding to believe. In particular, I might decide to believe my friend's story. If that's something I really can do, then I'm not just deciding to do something, I'm deciding what to believe.

There are other cases that aren't quite so direct. Think about belief in God. Pascal long ago observed that if I start going to Mass, taking holy water, spending time with believers, I may well come to believe myself. Of course, this won't work unless I'm at least open to the belief, but the point is that I can choose actions that make belief more likely.

So there's no hard and fast answer here, but it's plausible that at least sometimes and to some extent we really can choose what to believe in and even what to believe.

There has been much made of Hawking and Harris using brain scans to demonstrate

There has been much made of Hawking and Harris using brain scans to demonstrate a deterministic explanation of "free will". My question is, how do they treat a case where I think about moving my arm, but don't? How can the experiment they site test thoughts, subjective experience, etc. which do not lead to any outward physical effects? Must we accept that for all cases of mental phenomena that the brain scan test constitutes a proof?

Must we accept that for all cases of mental phenomena ... the brain scan test constitutes a proof?

I think the important philosophical question here is "A proof of what?" Suppose that science did somehow establish that all of our choices are causally determined by our earlier brain states. According to compatibilism, that result wouldn't threaten free will at all, and according to many compatibilists it would be good news indeed for free will. Before we get too hung up on whether brain scans are evidence in favor of determinism about human choices, let's ask the prior philosophical question "What difference would that make for free will?" You'll find this issue discussed many times on this website, including here:

Question 5451
Question 5711

Suppose we are to believe that the soul exists. If the body is extinguished upon

Suppose we are to believe that the soul exists. If the body is extinguished upon death, then is any type of afterlife in which the soul survives impossible? To me, the body is the soul's material basis; the soul is the functioning of the body. Consequently they cannot be regarded as separate since they are but separate names referring to a single object. For example, the soul is to the material basis as sharpness is to a knife; the body is to its functioning as knife is to sharpness. "Sharpness" does not name knife nor "knife" sharpness. Nevertheless, without sharpness, there is no knife; and without a knife, there is no sharpness. I have never heard of sharpness surviving the destruction of a knife; how then can we accept that the soul survives after the body has died? Or is soul something else?

This is a terrific question, even though you must admit that you are assuming all sorts of things: above all that the soul is the functioning of the body, and that the body is extinguished with death. One important tradition in thinking about immortality of the soul refuses to accept the former of these. That is the Platonic tradition, which believes that it can conceive of and define the soul independently of this material functioning. On that tradition, the puzzle you are raising does not come up.

However, the tradition that begins with Aristotle does indeed understand the soul as your question assumes, and there are even strains within Platonic philosophy that do the same. Certainly Christianity, with its belief in the resurrection of the body, proceeds with the thought that immortality must be grounded in the body's continued existence. So let's acknowledge that your assumptions are not shared by all theorists on the subject and press on.

One question the defender of immortality might still press you on has to do with your claim that sharpness does not survive the destruction of a knife. Surely that's false. One knife goes, but many others survive. No more of that knife; plenty more sharpness still around. Get rid of all knives and razors and physically sharp things, and yes you will thereby get rid of sharpness. But it's not as easy as banging up a single knife. What I think you mean to assert, in other words, is that sharpness (and therefore soul) requires some physical instantiation. Let's grant that. It doesn't follow that sharpness (or soul) requires instantiation in a particular object. Why can't there be another body in which my soul persists after the extinction of the body that defines me now?

Again, the Christian tradition apparently believes just such a thing; hence remarks about the body of the resurrection. And even that contrary thinker Plato can be interpreted to agree with this tradition. As early as the Cappadocian philosophers, in the generation before Augustine, we have what purports to be Macrina's deathbed discussion of immortality (as either transcribed or composed by her brother, Gregory of Nyssa). Macrina refers to the reincarnation or metempsychosis found in most of the Platonic dialogues' discussions of immortality. According to Plato (usually) the soul can pass from one human body to another, or even to the body of another species. Macrina would not make either assertion, yet she thinks Plato is on the right track. For what reincarnation acknowledges, according to her, is the need for souls to persist in some body or other. Plato just didn't see that there could be a unique body for one's soul to go into after the nonexistence of the present one.

These suggestions are not the end of the story. The conversation needs to go on at great length after Macrina/Gregory, and contemporary Christian theologians, among others, have taken it much further. My only point was to suggest to you that even assuming a view of the soul like the one you hold, there is a way of conceiving of its existence after death.


Hello, My name is Kyle, I'm a physics student. I have zero training in philosophy, save for an introductory philosophy course in my freshman year. I've been thinking about something quite frequently, and would like to hear an opinion from somebody who is knowledgable in the subject; The mind and the ego is a construct of the brain( at least as far as I know), and it's experiences. And I think it's fair to say that the brain is a clever organization of atoms, in what is essentially a computer. It has memories, which I think forms the ego, in a seemingly contiguous storyline. The hardware of the brain is however constantly changing, with atoms being lost and gained, through cell death, reproduction, respiration, and other biochemical functions, and yet our subjective experience remains. Suppose this effect is recreated in hypothetical setting where it is possible to create an exact replica of a person(A) to an artificially constructed person (b). Now, the copy is an exact replica, with every...

Good for you! You've stumbled on a central question in contemporary philosophy, and the thought experiment you offer is very similar to ones proposed by (among others) philosopher Derek Parfit, whose views on this question are much-discussed. The problem is what makes someone the same person over time. Put another way, what makes a person at one time the same person as a person at another time? The standard term for the bundle of questions here is the problem of personal identity. Usually, having the same body/brain is enough; your example points out that this might not be the only thing that matters. In particular, someone might think that continuity of consciousness is what's needed. The 17th-century philosopher John Locke held a view like this.

As you'd expect, different philosophers have come to different conclusions. Parfit thinks that identity is shallow and not what we really care about. On Parfit's view, psychological continuity is what matters, and he would say that in the case you've offered, we could say that A has survived; the copy, for all purposes that matter, is A. But Parfit thinks that the "is" here doesn't matter as much as we might think. Suppose the process doesn't destroy the original A-body. In that case, Parfit would say that the person in the original A-body and the copy are both psychologically continuous with the earlier stages of person A. A's consciousness has, n effect, divided. On Parfit's view the question of which person is "really" A is a shallow one. We could say that nothing have equal claim to being A. But they can't both be A, because two people can't be one person. So on Parfit's view, neither of them is A. Nonetheless, since both of them carry A's consciousness forward, what's happened is at least as good as ordinary survival from A's point of view.

My own view is that we understand all this less well than many philosophers tend to think, but that's neither here nor there. One place to start exploring the question further is by reading the article on personal identity in the Stanford Encyclopedia of Philosophy. You can find that HERE