Oh, some Kantian stuff here, and Waking life, nice.
a. Some people and events surprise me more than I could surprise myself when I dream. So I believe
it's not all in my head. Other people exist.
b. We have strikingly similar understanding of the majority of information. And since we are all different, separate brains, then
objective reality exists.
c. We also have perceptive differences, so our
perception is far from perfect. Each one is cognitively deceived in specific, defining ways.
Is perception reality? Subjectively, yes. Objectively, no.
Is reality merely a perception? --||--
"My perception is your reality" Subjectively, my perception of you is all that your reality will ever be for me. Objectively, I can influence your reality with my (wrong) perception of it, because I'm also part of reality, but one single perception, like mine, could never be all that your reality is. Even the total sum of perceptions of humanity of all times could not become your full reality, because you still have perceptions of your own, that were not influenced by any other perceptions.
edit: In the same context, I often wonder "What is proof?" ... I'm not satisfied with how dependent proof is on other people. If you are surrounded by blind people, you can't prove them colors. At the same time you could prove them things that are actually false. And here comes intuition. What if some things are obvious for me, that aren't for someone else. It turns out that it's more important for me to be able to prove the truth to the others, than just being able to find the truth. Cause if nobody could understand what I mean, then my knowledge becomes useless. It's really interesting, and frustrating at the same time. I'll give a concrete example with tests, on which you could identify the correct answers fast and accurately, but not being able to explain your reasons to a testing person. Which skill is more important in the end? Hard to determine, because collaboration is very important.
"if she this deny what can granted be..."