As a mind with no consciousness and sentience can't exist, we can reach a conclusion that a person who is asleep has no mind (at that moment, that is). — BlueBanana

This requires a very precise understanding of mind, since the mind does reawaken. There is continuity of some sort as memory is recalled and intention once again exerts will.

Having been unconscious, the actual feeling is that of no memory and no intent to perform some action, but something is still there that causes be to wake up and recall what I have learned. Call it the spark of life or spirit if you will which brings the mind to action again.

(Y) This is far superior.

This requires a very precise understanding of mind, since the mind does reawaken. There is continuity of some sort as memory is recalled and intention once again exerts will. — Rich

I agree with this, but is the existence of the mind required during that time for these claims to remain true?

Having been unconscious, the actual feeling is that of no memory and no intent to perform some action — Rich

I believe this might be a poor phrasing of what you mean, as I assume you don't mean unconsciousness is (necessarily) followed by amnesia? As for the lack of intent to perform actions, does the same not hold for waking up?

I believe this might be a poor phrasing of what you mean, as I assume you don't mean unconsciousness is (necessarily) followed by amnesia? — BlueBanana

It does appear to be what one might call "temporary amnesia", since observation of memory is not there. There can be disagreement if what is memory, but it doesn't appear to be there in an unconscious state.

In my own experience, reawakening did not appear to be a willful action. Ditto for waking up from a dream. The experience is qualitatively different from experiences when I am awake.

BTW, I believe this question is the most important one that can be asked when inquiring into the nature of life and mind.

Edit: treat this comment as if it didn't exist, I misunderstood.

It does appear to be what one might call "temporary amnesia", since observation of memory is not there. There can be disagreement if what is memory, but it doesn't appear to be there in an unconscious state. — Rich

Indeed, and I think the lack of observation is the significant part. Are the memories not there, or are we only not remembering them? Our brain does have the memories as electric signals, but does the mind, assuming it's not only a product of chemical interactions, have them?

Our brain does have the memories as electric signals, but does the mind, assuming it's not only a product of chemical interactions, have them? — BlueBanana

This would go under the title of "What is memory". My view it's that it is energetic and not chemical, and it is not located in the brain. But for this particular question, it doesn't appear that the nature of memory is relevant. It is sufficient that we agree that in a state if unconsciousness there is no sense of memory.

The way I see it is that a person may exist only when they are conscious (i.e., we "die" when we go to bed but are "resurrected" when we wake up) - but that the ethical implications surrounding people extends beyond their material existence.

We have (prima facie) duties to the dead not to desecrate their graves, steal their shit or slander their image, even if they're not around to know anything about it. We have duties not to kill people in their sleep - the fact that we can say we can "kill" them (even if they don't "exist" at the time of killing) means we recognize that there is, in fact, some sort of "residue" left behind that is morally relevant. Just because it's a memory or an idea doesn't make it any less "real".

Maybe we can call some of this residue "preferences" or "interests". But there's also the case that people who have lived a long time are entrenched in their community and killing them would involve permanently taking-away this asset of the community. So we can also see the morally relevant factors of someone's "footprint".

It's not often recognized that ethical debates don't usually revolve around principles or values or whatever but more around metaphysics. The abortion debate largely revolves around the metaphysics of persons, self-hood, identity, etc. Those opposed to abortion often say a fetus is a person that must not be killed, whereas those who think abortion is permissible will say a fetus is not a person and therefore cannot be killed. Nobody really disputes that killing people is morally wrong - what they disagree on is whether or not a fetus is a person that can be killed.

Those opposed to abortion usually say there is something "about" the fetus that makes it morally relevant - the Aristotelian version is that the fetus has a "telos" (to mature into a baby in the same way an acorn matures into a tree), and that having an abortion permanently frustrates this telos. It's also commonly held that the fetus has a "soul" and therefore quite literally is a person.

How I see it is that an unborn fetus or zygote or whatever has no conscious intentions, aspirations, preferences, etc, and the only real footprint is has in this world is that it's a constant memory of an oftentimes "accidental" sexual act. Any "telos" is may or may not have is not intrinsic to it but applied by external constraints as well. I'm resistant to this teleology - things happen in the world but there's no "function" to them that isn't derivative from more general principles. I'm also an atheist, and I don't think souls exists. So it's somewhat hard for me to be opposed to abortion, although I understand why some people might see it as murder.

Thoughts — BlueBanana

"Consciousness" and "self-awareness" are features of mind of which we are especially fond, but they are not the only components of a person. The brain where "I" dwell does not close down when a small cluster of cells in the brain stem sends the consciousness into abeyance and I fall asleep. (Another cluster of cells near by signals the consciousness to come back in full force, and I wake up.) While sleeping, some areas of the brain are quite active. Memory, for instance, is being processed. We dream, and while we dream the brain paralyzes are muscles so that we do not thrash about. Plus the small clusters of cells that watch over blood pressure, heart rate, respiration, peristalsis, and temperature are active all the time--24/7. All of that goes into "me".

There is so much about us that is processed out of reach of the conscious mind. "I" am witnessing some of these words flow into the computer through my fingers. I am not consciously composing the sentences, for the most part. Composition flows from below, through the motor cortex and the 9 busy fingers (my left thumb doesn't do much on the keyboard.)

As one drives, bicycles, or walks one doesn't calculate the arc of a turn -- one just turns. Clearly some facility in the brain has figured out how the curve can be negotiated, but I am not aware of it. Only when we do something unusual do we consciously think about it. I consciously figure what size can on the shelf is the best deal. When I come across a French word in an English novel, I'll try to guess what it means, and decide whether to look it up in the French dictionary.

Then too, our body is part of the unified self. We disposed of mind/body dualism, right. My arthritis-annoyed knees, shoulders, fingers, and ankles sometimes wake me to complain. "Wouldn't a little anti-inflammatory be nice about now?" they say. Or maybe we awake aroused and turned on. Or feeling sad. Or feeling hungry. Or full bladder. Or nauseated. Or any number of things that is part of our experimental 'flow'. Sometimes we wake up feeling existential despair--not just thinking it, feeling it.

"Consciousness" and "self-awareness" are features of mind of which we are especially fond, but they are not the only components of a person. — Bitter Crank

But are they the main component? Is it possible for the sub-consciousness, for example, exist without the conscious mind?

There is so much about us that is processed out of reach of the conscious mind. "I" am witnessing some of these words flow into the computer through my fingers. I am not consciously composing the sentences, for the most part. — Bitter Crank

I disagree. Because of the trivialness of the situation, you're not consciously considering each option or decision you could be making but you're still conscious of your actions. In a sense, you're conscious of each button of the computer you're pushing and each sentence you compose.

Similarly in your example of turning with a car, one is aware of turning, by how much and how much they are turning the steering wheel. What they're not conscious of are only the options they're not picking.

Then too, our body is part of the unified self. We disposed of mind/body dualism, right. — Bitter Crank

Whoa, let's not jump into conclusions quite yet ;) Even if conscious mind is not all there is to the mind, that does not disprove dualism by itself. And whole another thing to think of is p-zombies, or the opposite scenario of a mind with no body (both being hypothetical of course).

the Aristotelian version is that the fetus has a "telos" (to mature into a baby in the same way an acorn matures into a tree), and that having an abortion permanently frustrates this telos. — darthbarracuda

I don't have the time to go more into detail concerning your response right now, my apologies, but might you know the aristotelian stance on whether keeping a rock on a table is morally wrong as it's perturbing the telos of that rock, which is reaching the ground?

Is it possible for the sub-consciousness, for example, exist without the conscious mind? — BlueBanana

First off, my apologies for not reading this thread earlier (I gave a half-behinded reply to this topic on the thread about contraception being murder).

To contribute, one can simplify things by framing the issue in terms of dichotomizing the following two, rough-sketched alternatives of mind: either a) mind is itself inanimate or, else, b) mind is itself animate. If the first, mind devoid of conscious awareness is itself devoid of agencies; if the latter, then mind devoid of conscious awareness is endowed with agencies (or can be in healthy circumstances).

To not seem like a BS-otoligist (sorry, maybe poor humor), been toying with this near-Hume like hypothesis. Rather than affirming as Hume did that there is no first person I/self to the commonwealth of mind, wouldn’t it be better to affirm that his bundle theory of self is a stratified hierarchy of agencies (all causally tied into the plastic operations of neural webs within the brain at the lowest levels of agency) which, then, builds upon itself till the pinnacle of the conscious I is obtained? If so, for example, when we go to sleep what would occur is that the conscious I, in a sense, dissolves into the lower levels of this stratification in the mind’s agencies; when we awaken, the conscious I becomes once again brought about by the agencies of mind as – to use a partly fitting allegory – a conductor to the orchestra of the mind’s agencies. When dreaming, this conscious I is only partly composed out of the mind’s stratified agencies and, furthermore, interacts with other aspects of its own total mind’s agencies … I think for most, in very symbolic means.

More complex examples, such as states of comma, or vegetative states wherein only the so termed ‘lower brain’ operates, can then also make sense in such a model of mind. Though, here, the threshold between integral, living person and non-person can, at times, become fuzzy.

Mentioned this alternative so as to not be so half-assed given my previously made reply to you … As to spiritual musings, I think such an approximate perspective could make sense of the soul in the sense of anima … also of mind in the sense of the animus … this without requiring there being a homunculus (such as the soul being present and functioning even when we’re asleep and not dreaming).

the conscious I, in a sense, dissolves into the lower levels of this stratification in the mind’s agencies — javra

a conductor to the orchestra of the mind’s agencies — javra

I like your idea of consciousness 'dissolving into the lower levels' much more than Blue Banana's 'ceases to exist'. To play off your idea of the orchestra and conductor, let me propose a model based on the Orpheus Chamber Orchestra or the St. Paul Chamber Orchestra which perform without a conductor.

I suspect the conscious mind is produced by the brain, the same way a directorless orchestra produces music. The parts put it together and put it out there. Similarly the brain constructs our consciousness, but it doesn't 'spin it off' as a manager. Where is the brain's manager? There isn't one, there are several. For instance, whether you are awake or asleep isn't managed by your conscious mind. As I mentioned, there are two small cell-clusters in the brain stem that signal other parts of the brain to sleep or to awake. If people experience strokes in the wakeful manager, they go to sleep (not die) and don't wake up again -- because the trigger that wakes us up is broken. These two clusters don't do much else.

The conscious mind doesn't alone decide what it will think about, if it decides at all. There are 100 billion neurons between one's ears, and more connections possible among those 100 billion than there are atoms in the universe. So... whether the number of connections is real or hyperbole, there is clearly lots of power under the surface, and my guess is that it isn't waiting for the conscious mind to think of something. More like the other way around.

Where, for instance, do "intrusive thoughts" come from? Here you are, sitting in your chair reading a good book and annoying, distracting thoughts keep occurring to you. Who is sending these messages? Aliens? Hackers? Commie agents? Advertisers? Maybe it is a small area of the brain which monitors blood sugar, and it wants you to eat--so food thoughts burrow into your conscious mind's nice reading experience. Or maybe some memories of a slightly unpleasant nature are being accessed and the message of discomfort is being telegraphed to your front desk, covering up the text of the book your were reading.

Consciousness is emergent rather than a stable feature like language production. (We know exactly where language production is located. We don't know where consciousness is located.)

I don't have the time to go more into detail concerning your response right now, my apologies, but might you know the aristotelian stance on whether keeping a rock on a table is morally wrong as it's perturbing the telos of that rock, which is reaching the ground? — BlueBanana

To be honest I'm not entirely sure. I suspect only unities, or things with essences, have a telos but I'm just guessing. I get where you're coming from, cause the old Aristotelian physics held things fell to the Earth because that's where they "belonged". Even if a rock has a telos, it's not a permanent frustration of its telos to keep it from falling to the ground. I think this is how Aristotelians and the like get around the charge that, say, blinking, is morally wrong because it frustrates the telos of an eyeball to perceive light. But it's awfully convenient. Natural law theorists have often almost exclusively focused on abortion and abstinence, as if their ethical theory is fine-tailored to a specific view regarding these acts (but not so much in regards to other ethical issues - when in doubt, something-something Doctrine of Double Effect, who the hell knows really).

I'm not a fan of natural law theory, if you couldn't tell.

I can, um … vibe ;) … with just about everything you’ve stated. Yea, there are other allegories that can be used, like one where consciousness is like a horseman and its total sub/unconscious mind is the horse that is being ridden. Imperfect in that, to me, it lack’s acknowledgement of how consciousness is a forever changing product emerging from the unconscious mind. Bear with me a moment.

Still, like the conductor or the horseman/woman, the thing is we as a conscious agent either a) do our thing without any need for choosing anything consciously (much like the typing of a sentence where we don’t consciously choose which particular key to hit; or speaking, were we don’t consciously choose via deliberation which word follows the other) or b) choose by means of some deliberation between alternatives. Now, whether or not this choice is metaphysically free is a metaphysical question that can’t be answered via analysis of the physical—else it would have been long ago. In scenario (b) the alternatives are themselves the products of the mind’s agencies other than that of the conscious I. So the conscious I chooses one alternative at the expense of all other alternatives, and, thereby, in due measure, alters the plastic operations of its own brain’s neural networks … which then proceed on the path chosen by the conscious I (like an orchestra following a conductor’s flow, or a horse following the horseman’s pull on the reigns; the conductor doesn’t decide how each musician plays his/her specific instrument; the horseman doesn’t decide how the horse chooses to gallop on the specifics of the terrain).

OK, this would hold if i) metaphysical freewill is ontically real and ii) if we stop with the (to me greatly) incoherent notions of efficient causations between brain as one thing and mind as another; i.e., my brain doesn’t cause me to do something, nor do I cause my brain/body to do something; rather, this form of causation between conscious agent - total mind - brain and spinal column (i.e., the CNS, where neuron nucleuses are found) - and non-CNS-body is all, for the most part, simultaneously bi-directional (in simplified form, bi-directional between conscious agent and body) … this akin to how temperature and pressure are simultaneously bi-directional causal factors relative to each other.

And, yes, if we’re to indulge this model, there are many more complexities: e.g. tongue-tied speech, or slips of the tongue, or stuttering – to keep these examples all aligned with speech – would all be examples where the conscious I wills a certain X but the unconscious agencies of its mind are not unified on the same exact will being fulfilled by the conscious I as it intends (this for whatever reasons).

Oh, as to sleeping and wakefulness, notice that we as conscious agents can, to limited extents, willfully choose to stay up despite our total mind’s will of going to sleep. But again, whether or not this is itself due to metaphysical freewill on the part of the conscious agent is a separate issue.

All the same, if it needs to be stated, my own belief is that it is metaphysically free will in the form of the conscious agent bringing about effects from out of itself (its momentary identity of self) as cause - such as to the effect of which alternative it ends up pursuing … this even if the conscious agent is greatly influenced from without in what it ought to choose … but man, does this get into complexities. OH, just to be clear in advance, yes, I’ll likely be cowardly about things and chicken out of debating these complexities; if they get overly complex, that is … Just putting some possible perspectives out there.

The whole argument about free will and predetermination of an act is a waste of time IF we can not distinguish between acts that really are freely chosen and acts that are really determined by other factors. I think I can make that discrimination some of the time but not all the time -- and that is in my own case. I have only the vaguest idea of what is going on in your case (or anybody else).

Like, sometimes we find that we have done something without really intending to do it. "It just happened". Like, I wasn't intending to go to the bar and pick up a stranger and go home with him but you know, without my making a decision about it, that's what happened. It isn't that I was in a trance, or under the influence of drugs or alcohol. I just intended to go have a beer.

Now I have gone to the bar with every intention of picking up a stranger and going home with him, but not that time.

I wasn't intending to buy a blueberry pie when I was at the store -- I went in to get some milk, breakfast food, and some lettuce. But there the display of pastries was and I just picked up the pie and put it in the cart. Now, sometimes I intended to buy pie, but not that time.

When I started to write a paper on ethics and decision making in a time of epidemic transmittable diseases, I didn't intend to conclude that people should be quarantined if they are found to be infectious, but that's where the logic of my argument took me. Now, I have written policy papers with unpopular conclusions, but not that time.

Another problem with free will (or not) is that the agent about whom we are talking is also the agent providing the evidence for free will, or not -- a clear conflict of interest.

If we can't prove it on the basis of what the brain--producer of mind--is doing, then we just can't. Some philosophers (and neurologists) have suggested that we might not be able to understand our minds beyond a certain point -- because we are both the subject and object of that study.

Another problem with free will (or not) is that the agent about whom we are talking is also the agent providing the evidence for free will, or not -- a clear conflict of interest. — Bitter Crank

:D I take this to be irony, and find it indeed humorous. As to the complexities, what's new, the mind's complex. This complexity all boils down to that solutions / problems dichotomy.

I like your idea of consciousness 'dissolving into the lower levels' much more than Blue Banana's 'ceases to exist'. — Bitter Crank

I actually buy very much into that thought myself. I see mind as a construct that unconstructs itself into smaller pieces while asleep - a thought very similar to dissolving in my opinion. I just think just because the substance exist doesn't mean the construct does. If a building is demolished, all the concrete is there and can be used to rebuild, but the building is no longer there.

We have (prima facie) duties to the dead not to desecrate their graves, steal their shit or slander their image, even if they're not around to know anything about it. We have duties not to kill people in their sleep - the fact that we can say we can "kill" them (even if they don't "exist" at the time of killing) means we recognize that there is, in fact, some sort of "residue" left behind that is morally relevant. Just because it's a memory or an idea doesn't make it any less "real". — darthbarracuda

I guess we should be asking what anything being morally respectable is based on and whether it's justified to demand us to respect the dead to find the answer.

I don't know if I'm making sense but my 2 cents...

In the case of a sleeping person the brain structure of consciousness exists in full bloom. In other words, a sleeping person is merely taking a break from consciousness - a necessary one, for health.

A fetus, in the early stages of development, is just a clump of cells - lacking the neural structure necessary for consciousness. Of course, this claim is arguable but, the point is, without brain activity, a person is, quite clearly, lacking consciousness.

So, the fetus-sleeping person analogy breaks down because a neural structure (or brain) is necessary for consciousness.

One could argue, then, that the issue is that of potential for consciousness - both the fetus and the sleeping person being capabale of it. But, the fact is killing a sleeping person is murder not because a sleeping person has potential for consciousness. It's because a sleeping person is already conscious.

All that said, I'm assuming a scientific position.

All that said, I'm assuming a scientific position. — TheMadFool

There is zero evidence for anything you have stated, and yet you immediately place yourself under the umbrella of science for safety purposes. This is actually what science amounts to nowadays. One only has to create a story using words like neurons, brains, cells, structure, etc. and voila, one is shielded by science. It's exactly what is going on in the non-life to life thread.

Where in science does it explain how sleeping persons take a break from consciousness?

I agree with Rich. Science, as is, does not explain the emergence of consciousness, we can't equate the brain structure of consciousness with consciousness itself (even if we assume consciousness to be created by the physical brain) and being asleep is classified as a specific condition of unconsciousness ignore the last part, I decided to double check and am getting mixed results.

Scientists will give any one an A for any story as long as they use the words they want to hear repeated: brain, neurons, DNA, genetics, chemicals, robot, computer, synapses, etc. This is indoctrination.

Words that are verboten are: humans, mind, feeling, emotion, spirit.

Which is the science and which is the religion? Which is describing life as experienced?

I found my point of view on the metaphysics of a sleeping person's mind relevant and decided to contribute. As a mind with no consciousness and sentience can't exist, we can reach a conclusion that a person who is asleep has no mind (at that moment, that is). Of course, reaching into the topic that Victoribus Spolia started, we know that killing a person while they're asleep is a murder and morally wrong, which is because they're going to wake up, ie. they have potential to have a mind. But this is the argument Victoribus uses to justify opinion that most of us disagree on, that contraception is murder.

This is quite a dilemma I'm facing. One could ponder the relevance of the existence of physical body, but I find three counter examples to disprove this stance: first, braindead people are considered dead as they have neither mind nor potential to have one; second, dead bodies (similar to the former one except that the body isn't alive); and third, a hypothetical person with no body.

I believe the answer to be the existing social connections of a sleeping person, but this is slightly problematic as we wouldn't approve killing such a person. Alternatively a view on the metaphysics of soul that includes an afterlife might provide potential answers, as the sleeping person's mind (that didn't, at the moment, exist) would continue to the afterlife, but the soul of a person who never existed, would not. — BlueBanana

I've read something similar from Searle, about consciousness vanishing while we're asleep. But do we really have definitive empirical evidence that consciousness (awareness, sentience) is absolutely annihilated during sleep -- as opposed to say, sleep being merely an altered state of consciousness? Surely dreaming is a state of consciousness. Even exteroceptive cognition seems to continue at a subconscious level while we sleep, even to influence our dreams and perhaps our thoughts and feelings when we awaken. Further empirical investigation is required to flesh out our view of what happens to sleeping animals, or we might say, to sleeping minds.

It seems likely there are various "states of unconsciousness": different sorts of sleep, different sorts of coma, different sorts of anesthesia, different ways to be knocked out, and so on. In ordinary usage we may call a sleeping or KO'd person "unconscious", but it's up to empirical investigation to inform us whether there's anything like an "altered" state of consciousness that accompanies such phenomena.

Even if it's correct to say we are completely unconscious on certain occasions, we might nevertheless deny that our "minds" are annihilated during those periods. It seems ordinary consciousness depends on lots of subconscious and non-conscious cognitive activity. How much of the cognitive activity that continues while we are asleep and unconscious involves and influences cognitive function related to conscious activity before and after that period of unconsciousness? If there's any such activity ongoing, we might insist it is mental activity. Though the organism is momentarily unconscious, unconscious cognitive processes continue to manage the mind of the organism even while it sleeps, not merely keeping the body alive by maintaining homeostasis and metabolism and such, but also relaxing, healing, and reorganizing neural pathways involved in thought, memory, intention, affect, locomotion, and so on.

Arguably that continuity would be enough to support a claim that properly mental activity, in other words "the mind", persists even while the organism is unconscious. In that case, I would be content to speak of unconscious minds. I'm inclined to expect that something like this is the case for the sleeping animal.

Some thoughts with respect to the moral aspect of your question:

Of course a living human person, or any living thing, has a body. I'm not sure how your hypothetical case of a person with no body is relevant to the moral question. For one thing, you'd need to specify: How does one kill a living person who has no body? Or, what kind of killing is the killing of nonliving persons? How can we tell whether a bodiless person is alive or dead?

Disembodied persons aside, I'd say "a person has a mind", but not that "a person is a mind". Ordinary human animals are persons and have minds, but are not identical to their minds. Many nonhuman animals have minds, are sentient, but are not therefore called persons. Morality and law normally distinguish between humans and other animals. Even an agent who aims to treat all sentient beings with loving kindness won't treat all sentient beings in exactly the same ways, but distinguish them by their kinds.

Even if we're not satisfied with arguments, like those given above, that human minds persist during sleep, we should insist that human persons persist during sleep, even while their minds vanish. Accordingly, we say that rules against killing humans are not adequately analyzed as rules against killing things that are currently conscious or humans that are currently conscious, but rather rules against killing persons.

Then add: Non-human animals are not (necessarily) persons. Human corpses are not persons. Brainless embryos are not persons. Terminally brain-dead humans are not persons.

And so on.

the fact is, killing a sleeping person is murder — TheMadFool

It's murder because persons have rights that are protected by a host of conventions (legal, ethical, social, moral, religious...). Whether a person is awake or sleeping is irrelevant. Even if someone had been in a coma for 10 years, just shooting him or her would be murder (there are legal procedures for removing life support in cases of brain death or the patients previously expressed wishes...)

I guess we should be asking what anything being morally respectable is based on and whether it's justified to demand us to respect the dead to find the answer. — BlueBanana

I think morality is based on intersubjectivity. There needs to be at least two different subjective beings in existence for morality to have any worldly form.

i.e., we "die" when we go to bed but are "resurrected" when we wake u — darthbarracuda

This view appears a lot but I'll never be able to consider it because between the time I go to sleep and the time I wake up, I have extensive dreams. And I am changed by these experiences and my interactions in them. I am not the same person when I wake up. I actually start writing notes so I remember to type them up later into a journal.
There does appear to a mental 'reunion' of sorts for me upon waking, but that feels more Thomistic than Aristotelian.

There does appear to a mental 'reunion' of sorts for me upon waking, but that feels more Thomistic than Aristotelian. — JupiterJess

If mind permeates the body, then the cellular mind continues while the larger, imaginative mind moves through started of consciousness, dream, dream-like and unconsciousness. I suspect consciousness had multiple layers. However, this does not explain the Why? Why does the mind move through these different states? Forget about brain. It will not lead to any understanding or explanation.

Why does the mind move through these different states? — Rich

I'm still unsure about the evolutionary advantage of dreams anyway. It seems like it should be selected against since it presents false scenarios which could confuse the animal and get it into danger.
I can see the purpose of sleep. It puts the animal out of commission for a time when it is not at an advantage in its environment.
Perhaps evolution is the theory of the "fit enough" (like StreetlightX said recently) and the symbolic element of dreams provides animals with good enough symbols to help it most of the time. But then we're going back into Hoffman's illusion theory since it implies everything is like that.

I'm still unsure about the evolutionary advantage — JupiterJess

You would do best to set aside anything that biological science has to say about the nature of life. I believe the best and only path is direct observation of experiences, and experiences should be varied so that patterns of similarities and differences can be discerned. Biological sciences is hopeless and at the end, all you'll be left with is "It just happens"