true and correct

What's your take on this comment when related to prescriptive rules of grammar? Are there true, correct prescriptive rules for English grammar?

"It is possible that in business there is one way or a few ways that reap maximum profits--more than any other method. If you accept this as true, then you must accept that there can be true, correct prescriptive rules."

I learn correct English through dictionaries, grammar and English usage books. From them I learn about correct grammar and usage of words.

Presciprive rules of grammar and usage of words are like the laws of a country. If there were no laws, a country would be in chaos.

Similarly, if there were no rules in English, everyone could write in any way they believe is correct.

I think what people tend to forget is that English was not "invented" by some god-like group of linguists who first sat down and wrote up a list of prescriptive rules, and then went out and told everyone "Learn this brand new language.  Here is the list of rules. Don't speak this language any other way" 

Isn't the opposite true?  Hasn't actual usage always been the basis for the majority of prescriptive rules?  I mean, how in the world did it become "correct" that some forms of 'mail' are now countable?  Reputable dictionaries list "an email" as correct.  Plenty of people say things such as "I get more than 100 emails a week." and nobody accuses them of bad grammar.  Is electronic mail really any more countable than old-fashioned "snail mail"?  Did a bunch of prescriptivists sit down and decide the countability of 'email' in advance, later informing everyone that e(lectronic)mail is a countable noun?  Nope. The "rules" have clearly been dictated by speaker invention and actual usage.

Yankee

I think what people tend to forget is that English was not "invented" by some god-like group of linguists who first sat down and wrote up a list of prescriptive rules, and then went out and told everyone "Learn this brand new language.  Here is the list of rules. Don't speak this language any other way" 

Thank God you think so, Amy!
I always like it when someone says "Just because everybody says it, doesn't mean it is right". Well, the truth is the fact that everyone says it does make it right. Otherwise you should say "thou" instead of "you"... "you" is wrong even though everybody says it, because everyone is actually spoiling the English language.
I also like it when someone says something is non-standard, without saying what they mean by standard (since there is no such thing as a single standard). So I wonder if "aubergine" is a non-standard synonym of "eggplant". It sure is! People in the UK seem to use non-standard English.

Hoa Thai

In other words, in any language, words might be born as we search for a new way to express our thoughts, but they must satisfy some basic principle(s). In the end, wouldn't it be true that rules make up the foundation of languages?

Yes they do. All languages have rules. A usage is correct if all speakers in the speech community follow it.

Prescriptive rules are different - they are rules explicitly given and based on a person's or group of people's opinion of what is right and wrong. Prescriptive rules do not necessarily have anything to do with how the language is actually used.