Couldn't the Cogito be rephrased as something like: "I exist and I think, therefore I exist"? For if the 'I' doesn't exist, then it cannot think.
In this case, it is a tautology in a general sense.

However, I take issue with this statement on a different level, since it supposes that thought is proof of existence; in other words if I do not think, I cannot prove to myself that I exist. It avoids asking what the 'I' actually is, and merely observes that this mysterious 'I' tends to think.

There are good arguments for panpsychism, one of them being that since humans have consciousness and humans evolved from non-human animals, these non-human animals should also have had some form of consciousness, albeit perhaps more rudimentary. The ancestors of these animals presumably also had consciousness. At what point can you say that a life form has no consciousness? Does it begin with the formation of a central nervous system? If so, there are many forms of central nervous system, so which one of these originated consciousness? At some point, consciousness presumably emerges from an organism, and this consciousness is an emergent property - it is greater than the sum of its parts. But if this is true, then that which is conscious is literally unaccountable, since it is not present in the parts that made up the whole.

A similar argument underpins the definition of life. A cell is living since it has the behaviors associated with living things, whereas amino acids and proteins do not. The seven commonly agreed upon criteria for life are:

It should maintain some balanced conditions in its inner structure. This is called Homeostasis
Its structure is highly organized.
It should be able to break down or build up nutrients to release or store energy based on need. This is called Metabolism
It should grow, which means its structure changes as time goes by in an advantageous manner.
It should show adaptation to the environment.
It should be able to respond to environmental stimuli on demand (as opposed to adaptation, which occurs over time).
It should be able to reproduce itself.
https://en.wikibooks.org/wiki/Cell_Biology/Introduction/What_is_living

Now, life doesn't always have these 7 criteria at all times. For example, a life form at the end of its life cycle does not change in an advantageous manner, rather it begins to break down. Similarly, a life form may never reproduce itself, yet we would consider an infertile human to be just as alive as the parent of seven children. In short, the behaviors considered necessary for biological life are not always present in life forms, but this does not mean that since one behavior is missing, the life form does not live. There is a difference between biological life and life itself.

To return to panpsychism - to have consciousness is to be conscious of something, aware of something. To have self-awareness is to be aware of oneself, and humans view this as the gold standard of consciousness. But if consciousness only requires awareness of something, then cells are aware of their environment, and plants are aware of the location of the sun, and so forth. Their behaviors are quite predictable, even if there is some difficulty in predicting their actions. However, the only reason that life forms are aware of their environment is because of the interactions of atoms and molecules between the environment and the life form. The behavior of the life form is probabilistic based on quantum mechanics. At the smallest scales, the behavior of subatomic particles is also probabilistic, albeit on a different level than the life form. But it is a question only of scale, not of kind. The probabilities of the subatomic particles inform the probability of a behavior arising from a complex life form, and it is known that this life form's consciousness is the result of behaviors between the particles of the environment and the particles of the life form.

So just as life may exist without some of the key criteria of biological life, consciousness may exist without some of its emergent behaviors. At some level, there is no difference in kind between a life form colliding with an object and changing course with an atom colliding with another atom and changing course. Both behaviors are probabilistic, even if one is more predictable than the other. One may make the argument that the life form has far greater mind than the atom, but it is incorrect to say that the atom has no mind at all, unless mind is defined to have specific characteristics such as the criteria for biological life. There is a difference between a biological mind (brain) and mind itself. Those that say 'obviously an atom cannot think' are missing the point. The atom obviously has no biological brain, but it still has behavior and awareness, and as such has some aspect of mind.

Wosret is right, in that Zeno was uninterested in the mathematics of infinity. There is a correct solution to the problem mathematically, but this only means that the paradox wasn't designed for a post-calculus world. Zeno makes obvious mistakes in his paradoxes due to his ignorance of the existence of different types of infinity, but the original paradox is Paramendian - one cannot become many. Parmenides viewed the world as a sphere containing no differentiation - all was of the same substance. From Wikipedia: "[What exists] is now, all at once, one and continuous... Nor is it divisible, since it is all alike; nor is there any more or less of it in one place which might prevent it from holding together, but all is full of what is." (B 8.5–6, 8.22–24). From this he asserts that time doesn't exist, since change from one state to another is impossible given this framework for understanding the world.

This view seems very strange if taken at face value - after all, we can obviously divide space and time into measurable quantities. The only way I have been able to make sense of it is by viewing it as an imprecise conception of the Primordial Existential Question, or why anything exists at all. For Parmenides, the appearance of the world is an illusion hiding the underlying singularity of all things. So viewing it in this way, Zeno's paradox can be reformulated as something like: "How can we proceed from timelessness to time, or from dimensionlessness to dimension, if we view reality as truly timeless and dimensionless?" The point is not to demand an explanation of how one moment becomes another or how space can be divided, but rather to fundamentally question time and space. In other words, we cannot use a yardstick when the concept of space is not yet defined.

I don't believe that ultimate meaning is unattainable. I'm just saying that the complete meaning of life, or complete Truth, is dependent on being aware of the totality of the opposite of life, which is falseness and appearance.

Consider a person blind from birth, who was never told that they were blind. Such a person could say "I am blind!", yet while this statement is factual, it is all but meaningless coming from them, for they do not have a memory of sight with which to compare their blindness. Alternately, if a sighted person were to suddenly become blind, the exclamation "I am blind!" would have enormous meaning to them, since they know full well the gravity of their loss.

In the same way that the blind person can state a meaningless sentence while they do not know the opposite state of blindness, so too can a person feel that life is ultimately meaningless if they assume that all which exists is appearance. I claim that nothingness is true, and something(ness) is false, yet for someone who believes that things, or appearances, are true, life lacks ultimate meaning. They look around and see a world of things, and believe that they themselves are one thing among these things. There is no contrast in such a world, no place of separation or division where a dichotomy may exist. They are merely one collection of particles interacting with a much greater collection of particles. There is some definition to be had here, but it is extremely limited. However, if they did not assume that they were a collection of particles, but were rather Life (nothingness) itself, then they would begin to make some progress in finding meaning. Note that this isn't a substance duality, since I am merely illustrating the difference between something and nothing.

There is infinite meaning in the difference between something and nothing. Something has dimension, it changes, it is complex, it has form, it has weight, it is limited, etc. Nothing, however, is dimensionless, unchanging, simple, formless, weightless, limitless, etc. This is why I say that Truth is unchanging; because it is nothingness. But notice that the words dimensionless, unchanging, formless, etc are dependent on things for their meaning. I must be aware of dimension if I am to comprehend its absence, for example.

This brings me back to the supposedly unattainable meaning of life. Since life (nothingness) is without limitations, it can actually be aware of infinite falseness, and in so doing, have a complete definition of Truth, also known as life. For this it would have to abandon all limitations, all mere appearances, so it wouldn't be merely human. It may in fact be something akin to the omnipotence and omniscience of what religions call God, of which the human mind is only a tiny part. All of this probably sounds quite Buddhist.

The full meaning of life is unchangeable and static, but full knowledge of this meaning involves full knowledge of all experience, which is infinite appearances. For example, if you are acutely aware of death in your life, life can become much more precious, much more meaningful. You do not simply assume that life is a given. The light is brighter because of the darkness, essentially.

Freedom is a somewhat different issue, in that it exists when imagination exists. Imagination is the opposite of assumptions, for if you just assume certain things to be true, you will not think, not imagine ways in which things could be different. If you look at life from a variety of viewpoints, then you have greater experience, and therefore greater meaning in your life. In fact, freedom increases with knowledge of the unchangeable meaning of life. Nobody can have the full meaning of life, since it is as infinite as the number of possible experiences one can have, but the more you find this meaning, the more it is synonymous with freedom.

In short, the meaning of life isn't some tiny definition that boxes humans into their bodies and makes them unable to act - rather it illuminates the truth that bodies and the universe are merely appearances, and life transcends these appearances.

Life has inherent (permanent and essential) meaning (definition, explanation, connotation).
However, meaning is not always known. In fact, life begins in an apparently meaningless sea of appearances. Life is ultimately inexplicable, therefore ultimately meaningless, as long as it is assumed that appearances (rather than life) are real. Appearances are deceiving, life is true.

Since life has inherent meaning, it is unchangeable. Therefore, it is not up to you to give your life meaning, but rather to discover the (unchanging) meaning of life.

If someone lives who is ignorant of the potential for great pain, and they live well, isn't their quality of life far better than someone who is acutely aware of every potential mishap and lives a life of fear?

These qualms about the 'ultimate' pain of death are a bit baffling to me. It seems that people complain about living since they are bound to think/feel/sense things, and by definition some of these things will be classified as good and some as bad, or some as pleasant and some painful, etc. Of course they will be, and chances are that as your body begins to die, unpleasant experiences will increase. Yet remember that events that you once classified as horrible, like skinning your knee as a child, or being without a toy as an infant, can now be borne with ease, simply because you have endured so much worse as an adult. Because you have a vast mental library of many good and terrible things, you can assign a more appropriate level of pleasure or pain to any new experience. Experiences do not happen without your interpretation of them, so only you can determine if the pain of death will be greater or less than any pain that you have endured in your life.

To put it another way, a person living in pain for much of their early life could find a partial cure for their ailment and live 60 years with only moderate pain, and be pleased and grateful that their suffering was lessened, even a little.
On the other hand, a person in moderate health could suffer from a debilitating disease for their final 60 years, in the same amount of pain as the first person, and be miserable the entire time. It's all a matter of perspective.

Minds and bodies are not separate. Nor is your body separate from the bodies of others. Your body arose from the matter of your parents and the matter of your body will be the soil from which other bodies arise. If you join the Army Corps of Engineers, your body becomes a part of a larger body.

In a similar way, your mind is not separate from the minds of others. The ideas in your mind flow outward to other minds, and your mind is a receptacle for the ideas of others. If you believe in a religion, your mind is joined with the minds of the faithful.

Bodies are a somewhat arbitrary division of the physical universe into apparently separate parts, when the reality is that the universe is a single body.

Minds are an increasingly arbitrary division of all experience into isolated units, but the reality is that what one thinks of as 'their' mind is actually a small part of the total mind.

Mind is more fundamental than matter (though both are technically false), but the universe did not arise from a mind. Rather, Being (The Soul, That-Which-Is, I) associated with falseness, and as it was mindless, assumed that falseness was true. Thus, the universe was born. Gradually, Being recognizes that the universe cannot be True, and so it gains the mind.

Truth is singular, Falseness is infinite. So, universes and the mind are infinite with infinite experience.

Yes, people here tend to use big words when short ones will do. Some of that is unavoidable, since the history of philosophy is littered with arcane words, and philosophy itself is, in my opinion, the search for the correct definitions to words. I often write a wall of text trying to explain a concept, and realizing that I went off on a tangent halfway through and didn't actually explain the thing.

If everyone could simply agree on the definitions beforehand, everything would be much easier. But that's the point, isn't it? Philosophy IS a semantic dispute. If you do it right, you realize that seemingly simple words gain subtle yet powerful meanings. You become changed in a way that is hard to communicate to others, since you now speak in a new language, even if you use the same words as everyone else. There is a powerful desire to make new words to fit these new meanings, but I think this is a mistake. The goal of philosophy should be to explain the deeper meanings of words, not confuse people with new ones.

I believe that the argument for the world as a dream isn't to say that the world is identical to a single human dream, but rather that since it is possible to be fooled as to what is real, it is possible that the entire universe is no more real than a dream. The fact that we can point out that it is more internally consistent and persistent than a human dream is irrelevant. It still boils down to a series of experiences that can be doubted.

In the end, the dream argument is more of an argument through metaphor than a logical argument. If you were to bring logic into it, you'd have to have an ultimate reason for something to exist, rather than nothing. Since there can be no ultimate reason, nothing can logically exist. Since 'somethingness' is logically untenable, it cannot be true. Thus, anything appearing to exist is false, such as dreams and balls and universes. The real fun begins when you begin to define nothingness, which is true.

What is this nonexistence that a person can go into and come out of? One must first decide what actually exists. If the universe is all that exists, then consciousness is an emergent phenomenon and necessarily ceases with the death of the body. This is one mode of thought. I would argue that this falls apart if you demand a reason for the existence of the universe, since there can be no reason that doesn't rely on the existence of yet another thing, ad infinitum. Something cannot come from nothing.

The other way of looking at it is that nothing exists. It is all about how you define nothingness, or rather how you can't define it, since nothingness has no definitions. An undefined state appears to be all things, but these things don't technically exist. In this way, nothingness is True and the universe is false. So all things have their basis in nothingness, including your mind and what you might call your 'soul'.

So let's discuss the concept of going in and out of existence. One can perhaps fall into a void in which there is no space, but if time still exists and definitions still exist then it isn't nonexistence. It may still contain all the laws of the universe and other concepts, perhaps even the mind. To fall further, one would have to abandon all concepts, all definitions. But there again you are left in an undefined state, a state where anything could seem to happen. It is a meaningless state, and since it is without time you spend no time in it. In fact, upon reaching such a state you immediately 'rebound' into all experience, since like dividing zero by zero all answers are possible and all equally false.

In short, you cannot cease to exist, for the core of your being is not based in the illusion of the universe but in the Truth of nothingness which does exist and from which all universes appear. The core of your being in a very real sense created them and you are now in the process of experiencing them, along with all the other manifestations of your core essence.