I conceive the proposition — like Frege and Russell — as a function of the expressions contained in it. - Ludwig Wittgenstein

"303. "I can only believe that someone else is in pain, but I know it if I am." — Yes: one can make the decision to say "I believe he is in pain" instead of "He is in pain". But that is all. — — What looks like an explanation here, or like a statement about a mental process, is in truth an exchange of one expression for another which, while we are doing philosophy, seems the more appropriate one.
Just try — in a real case — to doubt someone else's fear or pain."

6.45 : To view the world sub specie aeterni is to view it as a whole — a limited whole.
Feeling the world as a limited whole — it is this that is mystical.

What we find in philosophy is trivial; it does not teach us new facts, only science does that. But the proper synopsis of these trivialities is enormously difficult, and has immense importance. Philosophy is in fact the synopsis of trivialities.