Tractatus Logico-Philosophicus
Language pictures possible facts, while logic and the limits of expression expose why some philosophical sentences fail.
The world is analysed as facts rather than a mere inventory of things. Meaningful propositions picture possible states of affairs through a logical structure they share with what they represent.
Sometimes a sentence sounds profound because its meaning is hard to pin down. Wittgenstein asks whether we have actually described something, or merely created the impression of a description.
Logic determines the space of possible description; logical truths do not add ordinary factual information about the world. Some features are shown in the operation of language rather than stated as further facts.
Ethics and the sense of the world are not ordinary factual propositions. This gives them a difficult status without simply equating importance with empirical description.
Philosophy clarifies language rather than competing with science as another collection of factual theories. The ending questions the status of the book's own propositions, presenting them as steps that must ultimately be left behind.
A proposition's possibility of being false helps distinguish description from tautology.
The distinction is not a verdict that only measurable things matter. It is a challenge to the assumption that every important concern must function like an ordinary statement of fact.
Logical form is exhibited by representation rather than another represented object.
The subject does not appear as one more ordinary worldly fact.
Scientific descriptions cannot independently supply a purpose for the whole world.
Apparent philosophical questions may dissolve when their language is clarified.
The book's own status becomes part of its concluding difficulty.