The following are just a few miscellaneous selected excerpts from Ludwig Wittgenstein’s Tractatus Logico-Philosophicus, enough to intrigue you and perhaps encourage you to read the whole book. This was a small book published early in his career that used the form of mathematical proofs applied to philosophy. The paragraphs in the book were numbered, so that “proofs” followed from the previous propositions. Pay close attention to paragraph 6.54. And paragraph 7, which is the very last sentence in the book, has always seemed to me one of the greatest philosophical concepts the mind of man has ever come up with.

Tractatus Logico-Philosophicus

1.  The world is all that is the case.

1.1  The world is the totality of facts, not of things.

1.11  The world is determined by the facts, and by their being all the facts.

1.12  For the totality of facts determines what is the case, and also whatever is not the case.

1.13  The facts in logical space are the world.

1.2  The world divides into facts.

1.21  Each item can be the case or not the case while everything else remains the same.

2.  What is the case—a fact—is the existence of states of affairs.

. . . .

4.063  An analogy to illustrate the concept of truth: imagine a black spot on white paper; you can describe the shape of the spot by saying, for each point on the sheet, whether it is black or white. To the fact that a point is black there corresponds a positive fact, and to the fact that a point is white (not black), a negative fact. If I designate a point on the sheet (a truth-value according to Frege), then this corresponds to the supposition that is put forward for judgement, etc.
       But in order to be able to say that a point is black or white, I must first know when a point is called black, and when white; in order to be able to say, “ ‘p’ is true (or false)”, I must have determined in what circumstances I call ‘p’ true, and in so doing I determine the sense of the proposition.
       Now the point where the simile breaks down is this: we can indicate a point on the paper even if we do not know what black and white are, but if a proposition has no sense, nothing corresponds to it, since it does not designate a thing (a truth-value) which might have properties called ‘false’ or ‘true’. The verb of a proposition is not ‘is true’ or ‘is false’, as Frege thought; rather, that which ‘is true’ must already contain the verb.

. . . .

6.13  Logic is not a body of doctrine, but a mirror-image of the world.
       Logic is transcendental.

. . . .

6.4311  Death is not an event in life; we do not live to experience death.
       If we take eternity to mean not infinite temporal duration but timelessness, then eternal life belongs to those who live in the present.
       Our life has no end in just the way in which our visual field has no limits.

. . . .

6.5  When the answer cannot be put into words, neither can the question be put into words.
       The riddle does not exist.
       If a question can be framed at all, it is also possible to answer it.

. . . .

6.52  We feel that even when all possible scientific questions have been answered, the problems of life remain completely untouched. Of course there are then no questions left, and this itself is the answer.

. . . .

6.522  There are, indeed, things that cannot be put into words. They make themselves manifest. They are what is mystical.

6.53  The correct method in philosophy would really be the following: to say nothing except what can be said, i.e. propositions of natural science—i.e. something that has nothing to do with philosophy—and then, whenever someone else wanted to say something metaphysical, to demonstrate to him that he had failed to give a meaning to certain signs in his propositions. Although it would not be satisfying to the other person—he would not have the feeling that we were teaching him philosophy—this method would be the only strictly correct one.

6.54  My propositions serve as elucidations in the following way: anyone who understands me eventually recognizes them as nonsensical, when he has used them—as steps—to climb up beyond them. (He must, so to speak, throw away the ladder after he has climbed up it.)
       He must transcend these propositions, and then he will see the world aright.

7.  What we cannot speak about we must pass over in silence.


       —Ludwig Wittgenstein