Quotes From "On Certainty" By Ludwig Wittgenstein

I am sitting with a philosopher in the garden; he says again and again 'I know that that’s a tree', pointing to a tree that is near us. Someone else arrives and hears this, and I tell him: 'This fellow isn’t insane. We are only doing philosophy. Ludwig Wittgenstein

At the core of all well-founded belief lies belief that is unfounded. Ludwig Wittgenstein

476. Children do not learn that books exist, that armchairs exist, etc., etc. - they learn to fetch books, sit in armchairs, etc., etc. Later, questions about the existence of things do of course arise, "Is there such a thing as a unicorn?" and so on. But such a question is possible only because as a rule no corresponding question presents itself. For how does one know how to set about satisfying oneself of the existence of unicorns? How did one learn the method for determining whether something exists or not?477. "So one must know that the objects whose names one teaches a child by an ostensive definition exist." - Why must one know they do? Isn't it enough that experience doesn't later show the opposite? For why should the language-game rest on some kind of knowledge?478. Does a child believe that milk exists? Or does it know that milk exists? Does a cat know that a mouse exists?479. Are we to say that the knowledge that there are physical objects comes very early or very late? . Ludwig Wittgenstein

Where two principles really do meet which cannot be reconciled with one another, then each man declares the other a fool and a heretic Ludwig Wittgenstein

If you tried to doubt everything you would not get as far as doubting anything. The game of doubting itself presupposes certainty. Ludwig Wittgenstein

I act with complete certainty. But this certainty is my own. Ludwig Wittgenstein