Ludwig Wittgenstein (1889 – 1951)
Austrian-born philosopher who spent much of his life in England.
All testing, all confirmation and disconfirmation of a hypothesis takes place already within a system. And this system is not a more or less arbitrary and doubtful point of departure for all our arguments; no it belongs to the essence of what we call an argument. The system is not so much the point of departure, as the element in which our arguments have their life.
My aim is: to teach you to pass from a piece of disguised nonsense to something that is patent nonsense.
Though a state of affairs that would contravene the laws of physics can be represented by us spatially, one that would contravene the laws of geometry cannot. (3.0321)
"It is necessary to be given the prop that all elementary props are given." This is not necessary because it is even impossible. There is no such prop! That all elementary props are given is SHOWN by there being none having an elementary sense which is not given.
Nothing is so difficult as not deceiving oneself.
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 them: "This fellow isn't insane. We are only doing philosophy."