Tractatus Logico-Philosophicus

There are seven main propositions in the book Tractatus Logico-Philosophicus. These main propositions are meant to be finite and basic, so the writer, Ludwig Wittgenstein, believed that no prior explanation of them was necessary. The propositions follow:

1 The world is everything that is the case.
2 What is the case, the fact, is the existence of atomic facts.
3 The logical picture of the facts is the thought.
4 The thought is the significant proposition.
5 Propositions are truth-functions of elementary propositions.
(An elementary proposition is a truth-function of itself.)
6 The general form of truth-function is: [`p, `ξ, N(`ξ)].
This is the general form of proposition.
7 Whereof one cannot speak, thereof one must be silent.

Propositions 1-3 are focused upon a theory of language. What is explained in four and five are the mechanisms of an ideal language, while proposition 6 references form of language. But proposition seven is the proposition that interests me the most but ironically the one least explained.

Proposition seven is just good advice. I believe that can apply not to just the theories of language but in while actually using language. I suppose it is very similar to the American proverb "If you don't have anything nice to say, don't say anything at all", but I believe this phrase refers to something else, not just about being courteous. I think it extents to knowledge, that if one does not know or really understand a subject then do not pretend to. It is great to discuss something to learn or to teach but if not one of prior two reasons then please remain silent. Or maybe it concerns something as trivial as gossip, if you know you should not be talking about something then don't. This proposition is something that is very applicable to our everyday lives and that is why I enjoyed it the most.