Good question.

A somewhat correct but useless answer is that it arises from the complexity of the brain. We have no idea how though.

The philosophical answer is that consciousness arises when the outer is separated from the inner (outer being the world, inner being you) and at the same time when the outer in reflected in the inner (for example, when the brain creates a model of reality inside it). That contradiction between what you think is real and what is actually real, along with the separation of the ego from the whole, is consciousness.

The best sound bite I've heard for this one is that consciousness is a story the brain tells about itself. The idea is that what we experience as consciousness is a feedback loop of the brain producing and receiving its own stimulus. In addition to processing actual sensory input, out brains are also adept at creating signals which it can then process as if those signals were sensory input. What you eventually get is a constant hum of brain activity in which the brain is describing its own state

they dont know precisely.
But its an emergent property of the complexity of the brain.
A bit like how 'wetness' is an emergent property of water molecules:
one water molecule is not 'wet' nor is a 100
but the complex interactions of countless water molecules feels wet.

So one neurone is not conscious
but the complex interaction of countless neurones gives conciousness

Kurzgesagt has a good video about this, worth a watch: https://www.youtube.com/watch?v=H6u0VBqNBQ8

Basically, it argues, if I remember correctly, that there is no special ingredient apart from evolution pressure + time and if you consider that in a serious way you can see how consciousness can an emergent feature in some species.

The question of where consciousness comes from is one of the biggest mysteries of neuroscience and philosophy. While there is still no definitive answer, there are several theories and hypotheses that attempt to explain the origins of consciousness.

One hypothesis is that consciousness arises from complex computations that are performed by the brain. This view is known as the information integration theory, which suggests that consciousness arises when information is integrated across different regions of the brain in a coordinated manner.

Another theory suggests that consciousness emerges from the interactions between neurons in the brain. According to this view, consciousness is an emergent property of complex neural networks, which produce self-organizing patterns of activity that give rise to subjective experience.

There is also a growing body of research that suggests that consciousness may be closely linked to the ability of the brain to predict and model the world around us. This view suggests that the brain creates a model of the world and uses this model to predict future events, which in turn gives rise to conscious experience.

Ultimately, the question of where consciousness comes from is still an open one, and researchers and philosophers continue to explore this fascinating and mysterious phenomenon.

Ok so this can quickly become very complicated.

Traditionally, the dominant religions tend to suggest a conscious entity called God imparted it into some clay with its innate magic.

Modern interpretation suggests that living things that can sense things in their surroundings will do better than ones that can't. If you can't see or hear a bear approaching, you are more likely to be eaten, and the same holds true for your own food, shelter, and baby-making.

All that sensation is useless without a response to what is causing the sensation. So the ability to move towards food or away from a threat is important too. So these faculties tend to start with simple rules and build in complexity over time, bit by bit, depending on how helpful it is to survival. Memory of locations helps too - you can find likely places food will exist, and find your nest after leaving it to find food for your babies.

Centralising and organising all these sensations and reactions so you can connect cause and effect is probably the start of consciousness. It will become an increasingly complex system of sensations, filtering and consequential behaviours within an expanding mental map of the surroundings built from the memory of sensations.

Having a mental resource/memory means you can learn what causes specific effects in your surroundings, including your own movements and decisions. This is the basic form of self awareness - me as an interior mind Vs the world. This is an advanced form of consciousness.

This can happen if you can sense things, respond to things, remember things. It can become more complex if your sensory system can detect activity in other parts of its own senses to moderate/inhibit/emphasise your responses. You don't want to listen to your blood and heart all the time, you don't want to spend all the effort on controlling your breathing unless you need to.

This sensation of sensation, and the inhibition of sensations, is the mix of consciousness and unconsciousness that makes everybody who they are.

There are known physical things, like punches to the heqd and anaesthesia, that can halt consciousness. You can't see without eyes and you can't think without a brain, which is why brain damage and dementia can make people confused and change personality. It's also why we can do surgery and people don't feel it.

The way I see it, consciousness is the direct result of our brains being able to comprehend the world outside of us as well as us at the same time. It’s a human concept to explain the brains ability to perceive its self and the world around it

It's one of the biggest mysteries of existence.

Some theories include:

It is a fundamental part of the brain and is a natural process within the brain.

Another theory is it originates outside the brain, outside of the physical world. Our brain taps into it like a radio taps into radiowaves.

Another theory is everything is consciousness and we are all existing within consciousness.

To this day we have no scientific evidence for how consciousness arises.

It is the cruel trick the universe has bestowed on us so we can plan and envisage things that do not exist and be aware of our own mortality.

It “probably” only arose in mammals which is one of the last known branches of evolution. Again “probably” requiring a certain threshold of complexity born from repeated rapid evolutionary cycles, due to global extinction events.

Predators don’t seem to have much of it, and herbivores seem to have less. We’re omnivores and have evolved to take advantage of different environments and food sources. Evolution has pushed us (our ancestors) to be rewarded from living on our wits and this is helped by better ng able to plan and invent.

Did you know the unconscious mind doesn’t use language? Dreams are the way your unconscious mind talks to your conscious mind, sending flashes of the days download to your long term memory and your conscious mind inventing stories from the frames of data.

The more perplexing question is how does chemistry lead to consciousness, since that is all we are, the repeated exchange of electrons in non-uniform systems.

Oh! And google quantum consciousness, but it is a bit hokey.

I read a sci-fi series by Peter F. Hamilton that had a hyper advanced race of aliens called the Silfen that basically treated reality and physics as their play thing. I remember at the end a character asks one where consciousness comes from and the Silfen replied “beats me”. It’s one of those weird things where the physical smashes into the metaphysical. We can poke around with the brain and see how it affects consciousness but I’m not sure if we’ll ever know how a bunch of electric meat can make a feeling like love or a raw quaila such as the color blue.

we dont know yet. we cant understand what consciousness is.

​

there has been some nuance in and out of mindfullness and eastern meditation.

but, science hasnt been able to measure it, so its still a decentralized term

​

there is the classic nature nurture dynamic at play. which can shape your conscious awareness. but we arent really settled on that definition.

In metaphysics, there has been theories to help explain adjacent-phenomenon related to universal theories:

IE, string theory, quasi crystals/8 dimensional theory, etc. But these are all theories, mostly based on mathematical models.

I like what Vonnegut said about humans, frankly. We dont have any absolute answers, and we are all just here to fart around

[removed]

It's what everything is made of and it's the only thing that exists.

Please read this entire message

Your submission has been removed for the following reason(s):

Subjective or speculative replies are not allowed on ELI5. Only objective explanations are permitted here; your question is asking for speculation or subjective responses. This includes anything asking for peoples' subjective opinions, any kind of discussion, and anything where we would have to speculate on the answer. This very much includes asking about motivations of people or companies. This includes Just-so stories.

If you would like this removal reviewed, please read the detailed rules first. If you believe this submission was removed erroneously, please use this form and we will review your submission.

We aren't sure, and that's the only ELI5 answer that's possible.

Consciousness is a very complex topic both scientifically and philosophically. Can you even prove that I am conscious? Can you prove that your own mother is not just some automaton that responds to stimuli in a way you'd expect?