An Exercise in Philosophizing from First Principles

You want to know how you prove reality? Okay. So say you meet me on the street. You are with your dog. You and your dog meet me on the street. Fourteen years later I write a really amazing blog post about the encounter at Cowberry Filmflam. But you don't know that yet. You have no idea. You don't even know that Cowberry Filmflam exists. But then somebody who is not you or your dog or me tells you about the blog post, and tells you also, because this other person who was not a party to the original encounter on the street knows you and your dog really well, that they, this other person, suspect the blog post must be about an encounter between the author of the post and you and your dog. You read the blog post. Not only do you agree that blog post is about an encounter between the author and you and your dog, you actually remember the encounter because the encounter really happened and you were there. Your dog was also there. You look over at your dog, who has over the course of the past fourteen years gotten very old and come to look increasingly wise. You know that the dog cannot read the blog post, probably cannot even remember the encounter, but you have no doubt whatsoever, and should have no doubt, that the dog originally had a very real experience of the encounter.