“Nothing is more important for teaching us to understand the concepts we have than to construct fictitious ones.”

“Language disguises the thought; so that from the external form of the clothes one cannot infer the form of the thought they clothe, because the external form of the clothes is constructed with quite another object than to let the form of the body be recognized.”

“I am not interested in constructing a building, so much as in having a perspicuous view of the foundations of possible buildings.”

“The aspects of things that are most important for us are hidden because of their simplicity and familiarity. (One is unable to notice something because it is always before one’s eyes.) The real foundations of his enquiry do not strike a man at all”

“That it doesn’t strike us at all when we look around us, move about in space, feel our own bodies, etc. etc., shows how natural these things are to us. We do not notice that we see space perspectivally or that our visual field is in some sense blurred towards the edges. It doesn’t strike us and never can strike us because it is the way we perceive. We never give it a thought and it’s impossible we should, since there is nothing that contrasts with the form of our world.What I wanted to say is it’s strange that those who ascribe reality only to things and not to our ideas move about so unquestioningly in the world as idea and never long to escape from it.”

“But some of the greatest achievements in philosophy could only be compared with taking up some books which seemed to belong together, and putting them on different shelves; nothing more being final about their positions than that they no longer lie side by side. The onlooker who doesn’t know the difficulty of the task might well think in such a case that nothing at all had been achieved.”

“The mechanism which we don't understand is not anything in our soul, but rather that of the life of this expression.”