Can you prove that I exist?
You were able to write this question. You probably have hundreds or thousands of people who have seen you and spoke to you. You probably have a social security number, a birth certificate, hospital records, and other official documentation. If I want to talk to you I can look you up on Quora and send a message to you, and you will probably respond. If I walk up to you in the street I can talk to you, shake your hand, and see you. In your home there are billions of pieces of DNA that will match up with DNA in your hospital record.
This doesn't prove that you exist, there is still a minute possibility you are just a hologram in my mind and I am really just in the Matrix, but the possibility of this is miniscule. I am 99.99999999999999999999999999999% sure that you do exist. I can prove beyond a reasonable doubt that you exist. There is still doubt, but there is only a 0.00000000000000000000001% chance that these doubts are true, so I have to logically assume that you do exist.
So prove? No. There is still the infinitesimal possibility you don't exist, but in logical society you must exist.
Beyond a reasonable doubt, you my friend, EXIST!!!
I can't. You can. Sort of.
So there's this famous saying: "I think, therefore I am".
The reason it's famous is that the feller who came up with it was basically saying: "What can I conclude if I make NO assumptions?"
And that was the only thing.
Normally in logic, you need to start with some assumptions. So you can make an argument that goes: if all marshmallows are delicious, and this is a marshmallow, then it'll be delicious. But ARE all marshmallows delicious? IS this a marshmallow? What's a marshmallow, specifically?
If I call this brick "marshamallow", will it be delicious?
So this feller, Descartes, wanted to see what he could work out despite making no assumptions at all. He spent a lot of time thinking about it... and then thought, "Hang on, something's thinking".
I mean, he probably thought something way more profound, and he would have thought it in French, but still.
If something is thinking, then something must exist. And that comes out as "cogito ergo sum", which is often translated into English as "I think, therefore I am".
But, obviously, it has some problems. Are YOU thinking? I mean, if I have a dream where I think I am the Dread Pirate Roberts, and believe it at the time, that doesn't mean I really was that handsome devil. Similarly, you might be some kind of toad thing living in a cloud of gas who is having the weirdest dream of all time, thinking he had hair and a computer.
*I* might not exist. Even if you're thinking, who can say for sure if it's the thing that thinks it's YOU?
And am I necessarily thinking anyway? I mean, imagine that you could make a complete mind-state in a computer or something. Imagine there's a team of engineers, hundreds of them, who laboriously create a single mind state - memories, thoughts, the whole deal. Then they make a copy, and update it just a bit - slightly alter the thought pattern, maybe update the memories. And they do it again, and again.
Finally, they run the states in sequence, like a movie. And that sequence is you. Every thought, every emotion, every experience, created in a lab.
Are you thinking? Are you even reading this text?
There's no way to tell.
So my preferred version of cogito ergo sum pretty much comes down to this: something exists. We don't really know if it's thought. We don't know if it's "I". Maybe the statement "something exists" that you read earlier in the paragraph doesn't exist, and you only think you remember reading it. Pff. Who knows? But even if all of that is an illusion, and YOU are an illusion, something must exist to allow that to happen.
So... you can think (maybe), and that means you exist (maybe). And even if it's not you thinking, and even if the thinking itself isn't real... well something exists.
...and you might as well call that something "you", and the thing that's happening "thinking", and get on with your life. If it is your life.
Which it might not be.
But given how hard it is to prove YOU exist to YOURSELF, yeah. Proving someone else exists ‘aint happening.
There are a few possible ways of knowing. If I'm using observation as an example, I'll have to assume that this method I am using is in fact a valid way of knowing something. I'll also have to assume the boundaries of what is knowable through this method. To further clarify as to why this is an assumption, one cannot use observation to prove the authority of observation.
Also knowing requires at minimum a subject(observer), and an object(the thing being observed).
If you would of asked if "you" can prove you exist then that would be different. That would lead to the question, Can you know the existence of yourself?
But you didn't, you asked if "I" can prove you to exist. That then leads to the question, can I know the existence of things other then myself (which in this case is you), up to and including myself?
Hence, possible and not certain.
Edit: also depends on what satisfies your definition of proof!
Can you prove that I exist?
No I can't. And that's a fact!
- I can prove I have a Body and you have a Body because in both cases I can touch it, feel it and see it.
- I can prove that I have Mind because I am aware of the Thoughts I think and the Feelings I Feel.
- But I cannot prove that you have a Mind. I Believe you have a Mind because it would seem crazy if I've got one and you haven't. But I don't know for sure as I can never know your Mind from the inside, like I know my own.
The first part of you - Body - can be proven but the second part – Mind - can't.
All I am left with is the option of believing you must have a Mind, on the grounds that you and I are likely to have the same makeup...
No, but you can.
Choose a late night or an early day for silence. Close your eyes. Everything that you saw a moment ago dissolves into darkness. You don't know whether the things that you perceived a moment ago exist now because it is dark and it is silent. The universe disappears from your senses.
But you know of one thing for certain, that you exist. In fact, this is the only thing that you know for sure. This is the only thing that you can affirm with confidence.
But is it just a thought? Do you exist because you think you exist? (cogito ergo sum)
No. Never limit yourself there.
You must know that you exist because nothing else can invoke the idea of your existence other than your true self. The mind as we know it, is incapable of this feat.
Now that you know that you exist. You are ready for the next question ‘I know that I exist, but who am I'?
There's an easy test to prove existence. That's because everything which exists share at least a few common concepts which can be compared.
Open up the reply field and type the answers to the following. It'll be easier to push this window to one side of the screen. And then open a word processor in the other. Also, load your calculator or have one ready.
What's the year of your birth?
What's the day of your birth?
Subtract the two.
Add the digits together.
This is considered your tier number.
Assign numbers to letters (a=1, b=2, etc..)
Type your name and then below it the corresponding numbers to the letters.
Add these together.
Add those digits together.
This is your base number
Type your tier number, then a / , then your base number.
You'll notice they're both the same number!
And when both numbers of a fraction are the same it equals the number one.
This will work with any date and any name no matter where in the world you were born.
This is how the concept, "We are one!" first came to being!