In other words, the question "what kind of rule can I use to determine whether or not my use of my private language is proper?" can only be answered by reference to rules which originate from the sphere of public language. Not only is the language I am attempting to use private, and therefore incommunicable, but the rules for its use are likewise private, therefore in principle unknowable to anyone other than those persons who can articulate those rules in a public language - in which case they are not private language rules any more, but public language rules.

Almighty Wiki puts this well:

Wittgenstein explains this unintelligibility with a series of analogies. For example, in section 265 he observes the pointlessness of a dictionary that exists only in the imagination. Since the idea of a dictionary is to justify the translation of one word by another, and thus constitute the reference of justification for such a translation, all this is lost the moment we talk of a dictionary in the imagination; for “justification consists in appealing to something independent". Hence, to appeal to a private ostensive definition as the standard of correct use of a term would be "as if someone were to buy several copies of the morning paper to assure himself that what it said was true."

https://en.wikipedia.org/wiki/Private_language_argument

The Private Language Argument for Five Year Olds: words are only of use if more than one person uses them. — Banno

If more than one person used them, then how does the language qualify as being "private"? So there is no such thing as a "private" language?

Indeed that is the argument, I think, Wittgenstein is making - that there is indeed no such thing as a private language.

So my daughter squeals every time she sees a spider. I might conclude that *squeal* means "spider", or I might conclude that *squeal* means "I'm frightened". But the truth is that it doesn't mean anything in the linguistic sense. *Daughter squealing* means "spider"/ "frightened daughter" equally, in the same way that a footprint means a foot. It's a sign of...

But feet do not speak 'footprint', and though some people read footprints, nobody writes them.

Yes, Harry - well done!

See PI 189e

PI 207e:

Always get rid of the private object in this way: assume that it constantly changes, but that you do not notice the change because your memory constantly deceives you.

What Wittgenstein doesn't seem to take into account, and is therefore the deficiency of such a private language argument, is that the use of any word need not be justified. If you assume that the use of any particular words needs to be justified, you will fall for the private language argument, concluding that using a symbol in a way that no one but yourself can understand, is not a case of using language. The problem is that if talking to oneself, using symbols for one's own private reference, is not a case of using language, then what is it?

Indeed that is the argument, I think, Wittgenstein is making - that there is indeed no such thing as a private language. — PuerAzaelis

Then it seems to be a trivial argument.

How are we defining "language" anyway?

I don't know about you (you may be an internet bot or p-zombie), but the contents of my own mind, in which words are only a small portion, inform me of the state of the world, which includes my own body. Colors and sounds and smells and feelings are themselves the "words" of a "language" informing me of the ripeness of apples, the relative proximity of moving cars, what is for dinner, and the state of my empty stomach. Is that a "private language" between the world and I?

Bump.

So you still don't understand that shit even after four years.