What can I know with complete certainty?

[Compassionist]

I am completely certain of the following:

1. I am conscious.
2. I am typing in English.
3. I am not all-knowing.
4. I am not all-powerful.
5. I change.
6. I can't do lots of things I really want to do e.g. go back in time and prevent all suffering, inequality, injustice, and deaths and make all living things forever happy.
7. I do some things even though I don't want to do them. Here are some things I have done, currently do or will do even though I don't want to do them:

1. Breathe
2. Eat
3. Drink
4. Sleep
5. Dream
7. Pee
8. Poo
9. Fart
10. Burp
11. Sneeze
12. Cough
13. Age
14. Get ill
15. Get injured
16. Sweat
17. Cry
18. Suffer
19. Snore
20. Think
21. Feel
22. Choose
23. Be conceived
24. Be born
25. Remember some events that I don't want to remember
26. Forget information that I want to remember
27. Die

I am almost certain of the following:

1. I and all the other organisms currently alive will die. Every second brings all organisms closer to death.
2. My body, other organisms, the Earth and the Universe really exist and they are not part of a simulation or hallucination or dream or illusion.
3. Other organisms e.g. humans, cows, dogs, cats, chickens, pigs, lions, elephants, butterflies, whales, dolphins, etc. are sentient beings who feel pain.
4. Being a non-consumer is more ethical than being an autotroph, being an autotroph is more ethical than being a vegan/herbivore, being a vegan is more ethical than being a vegetarian, and being a vegetarian is more ethical than being an omnivore or carnivore.
5. Gods do not exist.
6. Souls do not exist.
7. Reincarnation does not happen.
8. Resurrection does not happen.
10. Organisms evolved and were not created by God or Gods.
11. 99.9% of all the species to evolve so far on Earth became extinct in 5 mass extinctions long before humans evolved.
12. Humans and other organisms do not have free will. Our wills are determined and constrained by our genes, environments, nutrients, and experiences. The reason I have put this one in the almost certain category is that it is possible that bodies, genes, cells, stars, planets, moons, galaxies, universes may not actually exist. These things could be part of a simulation or dream or hallucination or illusion. It is impossible to know with complete certainty. I could be a solipsistic soul experiencing the illusion of being in a human body on a planet in a universe or I could be a body without any soul - I don't know these things for sure, hence I am an agnostic. There are many hypotheses that can't be tested e.g. simulation hypothesis, illusion hypothesis, dream hypothesis, hallucination hypothesis, solipsism hypothesis, philosophical zombie hypothesis, panpsychism hypothesis, pantheism hypothesis, etc. Just because a hypothesis can't be tested it does not mean it is true or false. It just means that it is currently untestable.

[Compassionist]

[Replying to Compassionist in post #1]

Reviewing my position almost 2 years later ...

I am completely certain of the following:
1. I am conscious.
2. I am typing in English.
3. I am not all-knowing.
4. I am not all-powerful.
5. I change.
6. I know concepts, e.g. what a square or circle or triangle is.
7. I know apparent facts about reality, e.g. the Earth orbits the Sun, the Moon orbits the Earth.
8. I know how to walk, run, eat, drink, cook, shop, work, read, write, type, go to the toilet, cycle, swim, etc.
9. I can't do lots of things I really want to do, e.g. go back in time and prevent all suffering, inequality, injustice, and deaths and make all living things forever happy.
10. I do some things even though I don't want to do them. Here are some things I have done, currently do or will do even though I don't want to do them:

1. Breathe
2. Eat
3. Drink
4. Sleep
5. Dream
7. Pee
8. Poo
9. Fart
10. Burp
11. Sneeze
12. Cough
13. Age
14. Get ill
15. Get injured
16. Sweat
17. Cry
18. Suffer
19. Snore
20. Think
21. Feel
22. Choose
23. Be conceived
24. Be born
25. Remember some events that I don't want to remember
26. Forget information that I want to remember
27. Die

I am almost certain of the following:

1. I and all the other organisms currently alive will die. Every second brings all organisms closer to death.
2. My body, other organisms, the Earth and the Universe really exist, and they are not part of a simulation or hallucination or dream or illusion.
3. Other organisms, e.g. humans, cows, dogs, cats, chickens, pigs, lions, elephants, butterflies, whales, dolphins, etc., are sentient beings who feel pain.
4. Being a non-consumer is more ethical than being an autotroph, being an autotroph is more ethical than being a vegan/herbivore, being a vegan is more ethical than being a vegetarian, and being a vegetarian is more ethical than being an omnivore or carnivore.
5. Gods do not exist.
6. Souls do not exist.
7. Reincarnation does not happen.
8. Resurrection does not happen.
10. Organisms evolved and were not created by God or Gods.
11. 99.9% of all the species to evolve so far on Earth became extinct in 5 mass extinctions long before humans evolved.
12. Humans and other organisms make choices, but they are not free from determinants, constraints and consequences. Our choices are determined and constrained by our genes, environments, nutrients, and experiences. The reason I have put this one in the almost certain category is that it is possible that bodies, genes, cells, stars, planets, moons, galaxies, and universes may not actually exist. These things could be part of a simulation or a dream or a hallucination, or an illusion. It is impossible to know with complete certainty. I could be a solipsistic soul experiencing the illusion of being in a human body on a planet in a universe, or I could be a body without any soul - I don't know these things for sure, hence I am an agnostic. There are many hypotheses that can't be tested, e.g. simulation hypothesis, illusion hypothesis, dream hypothesis, hallucination hypothesis, solipsism hypothesis, philosophical zombie hypothesis, panpsychism hypothesis, deism hypothesis, theism hypothesis, pantheism hypothesis, panentheism hypothesis, etc. Just because a hypothesis can't be tested, it does not mean it is true or false. It just means that it is currently untestable.

[William]

[Replying to Compassionist in post #10]

It is certain that consciousness is that which can and does experience anything.
Therefore, if it can be observed that something is experiencing something, then we can be certain that consciousness is involved.

[Compassionist]

[Replying to William in post #12]

Thank you for your reply. How do I know if others (e.g. humans, cats, octopuses, cows, dolphins, etc.) are actually conscious and are not Philosophical Zombies?

[William]

[Replying to William in post #12]

Thank you for your reply. How do I know if others (e.g. humans, cats, octopuses, cows, dolphins, etc.) are actually conscious and are not Philosophical Zombies?

The same way you know that YOU are not a "Philosophical Zombie"? (whatever it is you mean by that)

If you absolutely are not, then niether am I. (If I am not, then niether are you).

[Compassionist]

[Replying to William in post #12]

Thank you for your reply. How do I know if others (e.g. humans, cats, octopuses, cows, dolphins, etc.) are actually conscious and are not Philosophical Zombies?

The same way you know that YOU are not a "Philosophical Zombie"? (whatever it is you mean by that)

If you absolutely are not, then niether am I. (If I am not, then niether are you).

Thank you for your reply. Please see: https://en.wikipedia.org/wiki/Philosophical_zombie to see what is meant by the term.

1. The core of the problem

You only have first-person access to your own experiences - your sensations, thoughts, emotions.
No one else can see or measure them directly.
So it is logically possible that every other organism behaves as if conscious but has no inner life (i.e. a “philosophical zombie”).

This is a metaphysical possibility, but not a scientific or practical one - because there’s no conceivable observation that could confirm it.

2. The argument from analogy

We reason by analogy:

Other beings have brains or nervous systems similar to ours.
They react to pain, pleasure, fear, affection, and novelty in similar ways.
When parts of their brains are damaged, their behavior changes in ways parallel to human consciousness disruptions.

Therefore, the simplest explanation (Occam’s razor) is that they too have subjective experiences.

If we denied this, we’d also have to deny that any human other than ourselves has consciousness - which quickly becomes absurd and self-defeating.

3. Evolutionary continuity

Consciousness likely evolved gradually as a survival mechanism:

Organisms that could feel pain avoided harm.
Those that could feel pleasure sought food, mates, and safety.
Nervous systems became more complex to support flexible behavior.

That means consciousness is not a miraculous human property, but a biological function that scales in complexity across species - from octopuses to cows to dolphins to humans.

So, assuming that only you are conscious would imply an evolutionary “magic jump” that has no evidence.

4. The behavioral and neurological evidence

Cats, dogs, cows, and pigs show REM sleep, curiosity, play, grief, and empathy responses.
Octopuses recognize individuals, use tools, and play pranks - highly flexible behaviors.
Dolphins and great apes pass the mirror test, suggesting self-awareness.
Human infants develop consciousness gradually, mirroring the evolution of animal minds.

If we treat all that as “mere mechanism,” we’d also have to treat our own mind as mechanism - and the distinction collapses.

5. The moral and epistemic humility argument

Even if we couldn’t be 100% sure, moral humility demands that we err on the side of compassion.
If something might feel pain or joy, causing it suffering without necessity is unjustifiable.

My Compassionism actually resolves the problem pragmatically:

When in doubt, assume sentience - and act kindly.

That principle aligns with science, ethics, and empathy, even if metaphysical certainty remains unreachable.

6. Philosophical synthesis

Solipsism says only your mind is real - but it can’t explain the coherence and independence of others’ actions.
Panpsychism says consciousness is fundamental and universal.
Inter-subjectivity (phenomenology) says consciousness is inherently relational - it’s through encountering others that we recognize ourselves as minds.

So, the best synthesis is:

You cannot prove others are conscious, but all evidence, logic, and empathy point overwhelmingly that they are.

[William]

[Replying to Compassionist in post #15]

You cannot prove others are conscious, but all evidence, logic, and empathy point overwhelmingly that they are.

Then, that is proof enough assume absolute certainty?

[Compassionist]

[Replying to Compassionist in post #15]

You cannot prove others are conscious, but all evidence, logic, and empathy point overwhelmingly that they are.

Then, that is proof enough assume absolute certainty?

Not 100% certain, but almost 100% certain.