Is the self all that can be known to exist?

[Angrboda]

"This statement is false." and "This statement is not true." are not equivalent statements.

They are. The definition of "false" is "not true".

Only within the confines of specific logical systems. English is not such a system. Is a meaningless sentence not true? Yes it is. Is a meaningless sentence thereby false? No, it isn't. Because "not true" can refer to other states than false. So, no they aren't equivalent.

 The first may simply be neither false nor true, which is what you've been arguing, that the meaning is indeterminate.

No. I'm saying something is either true or it isn't.

Below you are arguing that very thing. Regardless, saying something is either true or it isn't ignores whole classes of logics for a "classical logic only" stance. You can't support such a stance because it's purely arbitrary.

 The latter statement, known as the strengthened liar is true even if the statement is incomplete, unless you are now arguing that incomplete statements have determinate meaning and are thus "true" which is opposite of everything you've claimed.

I'm saying that when you look at "this statement is not true" you're looking at an incomplete statement because "not true" adds nothing to "this statement is".

Your deflationary account of truth is noted. Even if I accepted your conjecture that the "not true" adds nothing to the statement, "This statement is," is a perfectly logical and whole statement asserting that the statement exists. However, "This statement is," is not equivalent to "This statement is not true," no matter how deflationary you get. One is a statement about existence, the other is a statement about a self-referential proposition.

"It is not true that I am happy" is equivalent to "I am not happy" but "this statement is not true" therefore would be equivalent to "this statement is not" which is an incomplete statement, unlike "I am not happy".

Your example only works because you're assuming that happiness is a boolean state, so all you've done is restate your initial assertion that something either is or isn't true, only using happiness as your boolean variable. That's begging the question. No matter how many times you assert that something is either true or it's false (*using your equivalence) it won't make it so just because you said so. There are many logics in the world and none of them are less valid simply for disagreeing with you.

The truth is what represents reality, and that's all there is. Falsehood/non-truth is a concept regarding that which does not represent reality.... but that's just how we conceptualize our own mistakes regarding what doesn't fit with reality. Ultimately all there is is what corresponds to reality: truth. It's like how when we say something is "illogical" we are referring to something someone has said that is logically contradictory. They can say things that contradict reality, but reality itself can't be contradictory.  "Illogical" is a funny word really because it means logically contradictory.

And here you are asserting a correspondence theory of truth as if your mere assertion is enough to close it. I don't know if you're intentionally denying other theories of truth, or if you're just ignorant to the fact that there are alternative theories. You're on a little firmer ground with respect to theories of truth because they are not as arbitrary as systems of logic, but not by much. Simply asserting your favorite theory of truth doesn't make it so.

  If the latter statement is incomplete, then it's definitely "not true" despite your assertion of a deflationary theory of truth.

Neither "this statement is true" nor "this statement is not true" are complete because a statement has to have meaning before "true" or "not true" are added. "this statement is" can be true or not true? No.

It can be either. Your blindness to anything outside your ersatz logical realism has blinded you to the fact that it is a complete statement. Regardless, your point is moot because if we apply it to your earlier example, "I am not happy," then not happy can't modify "I am" on the same grounds. In short, all you're trying to do with this "completeness rule" is eliminate all self-referential statements as being meaningful. That's a high price to pay for a rule that you just pulled out of your ass. I for one will not pay it, and it's an arbitrary and dictatorial imposition upon natural language. What are you going to exclude next, pronouns?