I mean, he challenged me to prove that my mother existed, without seeing her. Obviously I couldn't.
You didn't have a phone number you could reach her with? You didn't have any memories of her? These are all sufficient evidence for her existence. And sufficient evidence is what we call "proof".
At the very least, you could tell him "I bet you a thousand dollars that I will later see my mother, when I go home" If he doesn't accept the bet, that's evidence he himself believes in the existence of your mother, as he expects to lose your bet.
His words babbling about "existence" mean nothing -- as his arguments connects to neither the present and the evidence you have now (your memories of your mother), nor the anticipated future. It's just babbling nonsense.
Thank you (and others who have posted) for helping me with this silly argument.
:) I'll let you know how things turn out. He's quite clever at thinking on the spot.
So I have a friend who I sit next to in class, and we talk about philosophy. Well today, he brought up that when people leave your presense, and you can't observe them any longer, you no longer have proof they exist.
Well I pointed out that it would violate the conservation of mass law, right?
So then, with a bit more prodding, I figured out that by "no longer exist", he means they exist in their world, but they no longer exist in mine. So basically you can't prove that anyone exists unless they're directly in front of you.
I'm really not certain how to go about answering this question. I mean, he challenged me to prove that my mother existed, without seeing her. Obviously I couldn't.
Is he right? Or is there some flaw in his argument, some fallacy that I'm missing?
I went through a few of the Sequences, and the closest article I could find was about not believing in the invisible. But in this case, he doesn't literally (I think) believe they just vanish, he believes they enter alternate universes that are selected when I come in contact them again.
My mind is boggled. I also apologize if this is dumb question, and it's common knowledge or has already been answered, and to my credit, I did make an attempt to figure out the answer before bothering you all. Thanks.