Quote Originally Posted by Statler Waldorf View Post

Do you know that even if you really believe that you know something it doesn’t mean that you do? You can’t get around this; in order to question whether knowledge exists you must appeal to your own knowledge and thus contradict yourself.

Do you know that people argue using even nominally baseless assertions all the time? You see you did it again, you appealed to your knowledge in the very conversation where you are questioning whether knowledge is possible or not. In logical reasoning that is actually the only proof for a logical certainty; any statement that can only be challenged by making a self-contradictory statement or position is considered to be a logical certainty. We know that knowledge is possible because anyone who challenges its possibility contradicts their own challenge because they appeal to their own knowledge in their challenge. You’re only going to tie yourself into knots questioning whether the second premise is true.
You don't seem to understand what I'm saying. I'm not appealing to "knowledge." Just because I might think I know something doesn't mean I do. I appeal to my experience, to what I observe, to my understanding of logic.

All of those things are flawed, however. They contradict themselves at times, to say nothing of grabbing holding of Truth. Because I "appeal" to something doesn't mean what I am appealing to has substance.

These concepts we have of "truth" and "facts" are in my view only colloquial expressions. At their height they express a generalized feeling about what is true and what is factual, or in the case of science, what can be shown through testing and experiment. That does not mean these things are Truth or Facts. Even now in quantum mechanics they are showing that the foundational laws of the universe do not always apply at the subatomic level. How can there be "knowledge" when even the basic understandings we have about the physical universe can and does change over time?

What? How could someone who doesn’t exist be “wrong”? Your statement above refutes itself because Descartes would have to exist in order to be wrong, and if he existed then he was not wrong at all. It’s the very definition of logical certainty.
Can you prove Descartes existed?