Is there life after death?

No. It's sad, and it's scary, but you don't "go anywhere" after you die. Here's why:

When someone asks this question, "do you think we go anywhere after we die?" what they are referring to is of course not the physical body, but the "soul". The "soul" as used by most, is a nebulous concept that is part consciousness, and part identity, the essence of "who the individual is".
The first major problem with this idea of life after death is that it ignores the physically derived nature of consciousness(1).

To be conscious is to be conscious of something. If we observe all of the things that the consciousness is conscious of, we find all of it to be done by the body and brain working together. We can only see insofar as we have eyes and the necessary brain functions to interpret signals sent by the eyes. All of the senses work in this way. Additionally every capability for a conscious state we have, we evolved that capability. We can see because DNA with genes allowing for sight outreplicated DNA that didn't have genes for sight. All other senses that make up experience of the external world exist for equally pragmatic purposes.

The mental and emotional contents of conscious experience were developed for pragmatic reasons as well. Storing information and recreating it as a memory is another kind of conscious state. Emotions are also conscious states. These conscious states are also attributable to their being useful. The feeling of happiness/euphoria gained through the pumping of certain chemicals acts as a reward for us. All of these types of conscious states are only allowed for insofar as our brains have the capability to produce them. And our brains only develop those capabilities out of usefullness; because the organism with these capabilities reproduces better.

So it's fairly obvious why we have each of our specific capacities for conscious states, if not why we have consciousness in general(2). If we take away all of these functions of consciousness, what remains? Exactly what would a conscious being experience without a body, outside of spacetime? If it did somehow have a sense of "where/how it was", it certainly wouldn't be able to feel any way about it, happy/sad/angry, because these are all functions of the brain. You can't see your grandma in heaven because there is no sight, and memories are clearly only stored in a well-functioning brain, so you wouldn't remember who your grandma was.

There's no reason to think, given the pragmatic explanation for the occurence of earthly experience, that an extra-spatiotemporal conscious being would have any experience like ours (sight, sound, emotions), because we do not know what it is like outside of our universe, what kind of conscious states would be necessitated into being in that environment.

Above I have outlined 2 arguments. The first supports the second. Here they are restated:

1. Being conscious is being aware of things.

2. The only way we can be aware of things, is through states made possible by the brain.

3. The conscious states made possible by the brain were developed by our ancestors' DNA for pragmatic reasons. (We can see colors because it is useful to see colors)

4. Therefore we seem to be able to fully account for why we have consciousness as it is understood.

The second argument for why we should not think there is extra-spatiotemporal consciousness.

1. We know why earthly states of consciousness came to be. They were pragmatic for DNA.

2. We have no reason to believe there is an extra-spatiotemporal realm of existence where consciousness exists in any form, or what kind of features an extra-spatiotemporal existence could have.

3. Given this, there is no reason to suppose that that extra-spatiotemporal plane of existence would lead to the creation of any kinds of states of consciousness, much less states that would be recognizable to us, and even less that our brains would send our memories there upon dying.

Our consciousness seems to have come about for a reason. But we don't know the conditions of other realms of existence. We don't know that things come about pragmatically in these places. What kind of consciousness could we suppose that would arise without pragmatic purpose? I suppose it would be a simple awareness of existence in general, but not any particulars which would require specific senses. It wouldn't gain an ability to see (or something similar) because we can't suppose that it would have reason to develop the capability. It would not feel good or bad. Why would such a consciousness come about? Is it even desirable? The answer is no, and here's the kicker: this consciousness, even if you became it, would not have the capacity for memory, it would not even know that it had been you. This severely undermines the purpose for devising a concept like "the soul".

In order to believe that "something" must goes on, one must posit an irreducible "soul" or some such entity--because we find that the only thing that can remain of "you" after getting rid of all that physically derived conscious content, is something with no content. But how could this content-less soul be "you"?

How could it be "you" without your memories? We know that memories do not survive death. The evidence is the simple fact of memory loss while alive. This gives memories a clearly non-transcendent nature. If your "soul" can lose the memories while it's still alive, what hope is left for the soul to hold onto memories after the full death of the brain?

What kind of defensible concept of the "soul" would have no memories of its previous life, no content that would make it recognizable as its previous self? In what meaningful sense would it even be a continuation of the sense being? I assert that it would not.

If we connect this point about physicality of consciousness to some of the common experiences of moving in and out of consciousness, the fact becomes even clearer: consciousness and the physical brain are inextricable.

Here's a brief timeline for how we interact with consciousness. First we don't exist. We haven't been born yet and so we aren't conscious. Then we are born and aren't really very conscious. That is to say, we do not seem to be aware of many things, and don't seem to be recording very many memories from this time period (from about age 0-5). As we get older we all have this unmistakable sense that our consciousness is gradually increasing on average. Most people say things like "I don't feel like I was really aware/awake until I was about 25". So conscious experience appears to shift in its intensity throughout a human life. And this doesn't only occur on the macro scale. When I take a stimulant I have the unmistakable experience of being "more conscious", and this change occurs in minutes.

So what can we gather from this rising and dipping, gradual and sudden, shift in the acuteness of conscious experience? Two things: for one it makes it ever more obvious that consciousness is derived from the body and its needs. For another, it gives us a window into the way that consciousness doesn't even continue uninterrupted through one's spatiotemporal existence, much less outside of that spatiotemporal existence.

Not only does consciousness not continue uninterrupted, but we can add in problems of identity. The body at all times is shedding physical parts, as well as shedding memories and conscious states. The person physically and mentally is in a constant state of physical and mental change. To think that "you" could continue after death, well there would have to be a transcendental essence of "you" to begin with, and there doesn't seem to be anything of the sort.

Someone may want to solve the difficult problems of discontinuity of consciousness by responding that there is continuity of consciousness, and we just don't remember these in between times.(3) I first read a similar claim from either Locke or Descartes, I don't remember. And I've heard similar things from new-agey individuals. But it's a big leap that doesn't solve any of the problems with the physicality of consciousness, the problems with the concept of a soul, or the problem of establishing a transcendental individual.

So I have explained why we should think that consciousness is fully physical, why alternative conceptions of consciousness would likely be unrecognizable, and shown how shifts in consciousness are constantly occuring throughout the life of the brain. In addition to this the final (and most decisive) reason not to believe in the continuity of the self after death, is that there is simply no good reason to posit it or believe in it. Just as with conscious states themselves, we can explain this idea perfectly as a kind of pragmatism: the belief in life after death is nothing but an adaptation created to deal with the pains and fears of temporary existence by temporary beings. The idea simply does not survive scrutiny. It has so many problems that the proper attitude towards it is not an agnostic "maybe" or "no one knows for sure", but an emphatic "no".

Notes:

(1) As Chalmers points out in his essay in Strong and Weak Emergence (2006), states of consciousness directly correlate to brain states. I.e. when one feels angry, this conscious experience is always accompanied by a brain state which allows for that conscious experience. Chalmers thinks that consciousness may be "strongly emergent", not deducible from low-level facts about the universe, but he would still maintain that you will not find a consciousness where there is no corresponding brain states or states like them in some other physical system.

(2) This is the probably the most controversial claim in this essay. Chalmers himself and many philosophers of the mind would dismiss me here, as he describes this as the "hard problem" of consciousness: why we have it, why we experience anything at all. But I argue it should be obvious that most creatures (from what we can tell through their behavior) have consciousness, and they have it because it is advantageous to have it. In the same vein as legs, most land animals develop legs because it was a huge advantage to do so. If it were not advantageous, they would not all have developed it. I think it's likely that consciousness is far more advantageous than legs, however, and probably more prevalent as well. This is all unless we subscribe to a kind of panpsychism in which consciousness is physically fundamental, where then every piece of matter has some measure of consciousness necessarily. But even if a rock has some consciousness, there still must be explained why the human developed consciousness far beyond the rock. And once again I think the same answer would fully explain it. The human developed more consciousness because it was more useful to do so. Perhaps you could have a consciousnessless creature who can see things but can't do as much with the information as a conscious creature. Or perhaps in order to have any method of detection at all the creature needs to have consciousness, which would necessitate that plants with means of detecting things are conscious. I think that consciousness must spur intelligent action in a unique way, that makes it vital to a creature that must make decisions.

I think it can at least be agreed upon that we see "signs" of consciousness in most animals. That is to say most animals appear to respond to stimuli in a way that suggests they are actively experiencing something in a way that is similar to, if less acute, than our way of consciously experiencing. If ever we determine how physical structure leads to a conscious system, we should be able to verify these things. Until then we are restricted to observing behavior. Behaviorism in psychology is considered a failed project, but I think it still can suggest that a being has consciousness. I would summarize this point by saying: why would something appear to be actively having an experience if it were not? And why would something avoid pain if it didn't have to experience the unpleasantness of pain?

(3) Here is an argument against that if we decide to take it seriously. Why can't consciousness leave the brain while it sleeps? After all, we can black out from alcohol and not remember, but this does not mean we were unconscious during this period.

To this I would say: even if we lack memories during a certain period of time (like drunkenness), we will still likely experience (and remember) the shift between this memory-less state and whatever state follows. That is to say a shift from one conscious state to another is something we can be aware of, and often are aware of.

Even if we shift from an unconscious state, to a conscious one, this shift can be felt/experienced. In fact it is often strongly felt.

A very stark personal example of this involves times when I've awoken from a dreamless nap. I always am frightened at this experience of transitioning straight from total unconsciousness to awake and alert consciousness.

This point goes against a statement like this: "Our consciousness leaves the body/goes somewhere else when we are asleep. It's just that we don't remember where it went". Also any statement that would involve consciousness "jumping" forward in time.

I first read a similar claim from either Locke or Descartes, I don't remember. And I've heard similar things from new-agey individuals. If we really had gone somewhere else, if the consciousness had fully left the body, we should never feel the shock of going from unconsciousness to consciousness. It should be more like gaining one's sobriety after a night of being black-out drunk. For this reason it doesn't make sense to believe that consciousness goes anywhere when the body is unconscious. Instead it is as it seems: it shuts off.

References:

https://soundcloud.com/samharrisorg/david-chalmers

In P. Davies & P. Clayton (eds.), The Re-Emergence of Emergence. Oxford University Press (2006)