I seem to have gotten myself involved in a debate on Linguistics. I couldn't respond to these arguments earlier because I was having problems with my Internet. But now that I have access again, here are my rebuttals. They start, in reply to my claiming they've misunderstood my point:

Maybe I did, but it's probably because we are not having the same understanding of the term "idiolect",

Let me point out that this clearly supports my view that different people assign different meaning to words which will cause misunderstandings.

which to me simply means: a personal use of a language by an individual in his speech.

Your definition is not in contradiction with my definition, and so it is not unreasonable for a person to use your definition and still come to the same conclusions I did.

But among speakers of the same language, the various idiolects are still based on a common language, where words are defined, if not exactly the same way, at least within certain basic understandings.

Here, you seem to be making the assumption that it's possible for two people to speak the same language, an assumption ingrained into a lot of people's mind, and one which I'm trying to get them to analyze and question. No two people speak the same language. That was the whole thesis of Misunderstanding and Misunderstanding part 2. Two people may have similar definitions for a given set of verbal symbols ("words", if you prefer), and they may have completely different definitions for another set. Again, recall the example of "fag" to an American and a British, despite their both speaking "English".

Idiolect does not mean: I'll use whatever words I want and give them whatever meaning I want.

Actually, that is exactly what it means. At least, that's exactly what it means to me. Your definition (and thus your ideolect) may differ.

To take the example of the word "lie", there has to be a difference between the concepts of telling a deliberate untruth and asserting something that turns out to be untrue.

Two issues here. The first is philosophical and rhetorical (i.e. you need not bother answer it; it's there to make you think): why do you think there has to be a difference between two concepts. The second is more serious in terms of pointing out a flaw in your reasoning: Why do you think that there has to exist a word to represent every concept which may differ.

That is to say, let's say we agree that there exist these concepts of "making a false statement intentionally" and "making a false statement unintentionally", and that they are two different concepts. Why do you think the word "lie" must apply to only one of them, and not the other? And who are you to decide which of these two concepts the word "lie" applies to?

Surely, you've heard the claim that Eskimos have 50 different words for "snow". The claim goes something like "They have a word for snow that has just freshly fallen, snow which has been packed tightly together, snow mixed with dirt, etc." Clearly, each of these 50 different Eskimo words represents 50 different concepts. And yet, we don't have 50 different English words to each represent these 50 different concepts. In other words, English does not have a word for every single concept conceivable. Thus it your implied assertion that there must be a word for "making a false statement intentionally" and a different one for "making a false statement unintentionally" is entirely unfounded.

If a child shows me a twonie and says that it was left under his pillow by the tooth fairy, I wouldn't call him a liar. But you probably would.

Now why would you make that claim? Are you assuming that my "preferred" definition of "lying" is "stating a falsehood, independent of whether it was intentional or not"? You shouldn't be making that assumption. As far as I can recall, I have not stated what my definition of the term "lie" is anywhere on my blog. What I have stated is that there exists people who use that definition. In particular, I did not state that I was one of those people.

I'm guessing this is the passage you are thinking of. Read it again, and notice that I have not given any indication of what my definition of lying is:

In particular, I was in an argument with someone a long time ago about the possible definitions for "lying". We had both read a text which contained the term "lying", and the other person felt that the author of the text was being offensive for falsely accusing people of "lying", where she interpreted "lying" to mean "to intentionally tell a falsehood". I pointed out that perhaps the author of the text meant "To tell a falsehood", without the requirement that it be intentional (thus making the author's text a statement of fact, rather than a guess at another's intent, and hopefully therefor less offensive). She disagreed, insisting that the only "correct" definition of "lying" was "intentional lying".

She could not seem to accept the idea that there might exist people who might associate a different connotation with the term "lying", and therefore could not accept the idea that the author had intended this "unintentional lying" definition.