How is a generalization not definite? It's a broad generalization, maybe, for lack of a better word, (edit: if it is intended to mean all flowers, which it most often is not. Therefore we say indefinite, a generalization is inherently objective, "I like flowers" is subjective, those don't mix well).

@Hectorvon In general and definite ones are different. "the" is a definite article (clearly defined or determined; not vague or general; fixed; precise; exact:)

@SovereignSun, i think that is a broad generalization, ie. vague. A generalization needs to be definite in principle. It's funny how general could come to mean the opposite of specific, although genus (whence general) means species.

@Hectorvon You should spend some time revising the usage of "the" and how it works in English. Believe me, I spent a lot of time studying articles. Why we say "World War 2" and not "The World War 2", why we say "I breathe air" and not "I breathe the air" when we mean the air we breathe. Why we say "I love nature" and not "the nature" when we mean our nature (in general), while there is only one unique nature, a definite one, clearly determined one.

I breathe air - search for go to the home to find an explanation.

World War 2 is a proper noun, those simply don't take articles.

I love the nature would not be wrong, the referent is simply implied to be known from shared context. wiktionary says about uses of the "4. Introducing a singular term to be taken generically: preceding a name of something standing for a whole class."

+1. Thanks for the flowers = thanks for the ones you know about (because you sent them). That unstated modifier ("the ones you know about") is the only specificity involved here, making this phrase of thanks rather perfunctory (absent any other spoken tonal effects).

@Hector von: That Wiki definition applies to contexts like The Larch or The African Elephant (e.g. books about the species). The "term" there must refer to something of which there are many instances, and Nature refers to the whole; there is only one Nature.

@TRomano -- "the" is also used when a single individual is meant to represent the entire class. "The manual for the '68 Mustang" refers to every copy of that manual, and it covers every example of the car.

@SovereignSun, All I was trying to say is, if "flowers" means all flowers, you would loose a simple way to refer to an undetermined amount, i.e. indefinite. Omission of any determiner leaves the amount, you guessed it, undetermined. This answer already pointed out, that's not the same thing as uncountable. However, all is a specific determiner, so a generalization over all the members of a group is in principle definite, by my estimate, because I fail to see the difference between definite and determined. I'm still not saying, "I like flowers" was wrong, but I am still confused.

@Malvolio: Agreed. That is precisely the implication of my comment.

Even with the specification "in your garden", there are situatoins where the definite article would not be used: "I'd prefer flowers in your garden" could be a reply to someone (re-)designing their garden and wondering if they should plant flowers or only lawn ... Of course, this makes it an utterance about unspecific "potential" flowers

@HagenvonEitzen You have to consider "I like... in your garden". My explanation is for a specific sentence using "I like" with a definite article, not a generalization of the use of the definite article - something that has already been discussed on ELL.

@Hectorvon: "*I like the nature" would be wrong. Abstract nouns (e.g. nature, love, literature) don't take an article except in very specific cases. "I like flowers" refers to "flowers in general", rather than any specific flowers. You don't lose a way to refer to an undetermined amount, because if you want to say "I like <an undetermined amount of> flowers" you would say "I like some flowers" or "There are flowers that I like".

@psmears, the sky is an abstract idea, the nature around us is concrete ... in a sense. As I said in my answer but removed, the difference would be more philosophical than grammatical. Maybe it's psychological, too. Anyway, "Some ..." and "there are" aren't formal, and in my opinion just redundant or even wrong. Somehow, signaling indetermination with a determiner is paradox (I presume it was a determiner). Worse, "There are ..." would really need "some" by your own line of reasoning, thus you kind of prove my point - or I fail to see what is indeterminate about "There".

@Hectorvon: No, the sky is not an abstract idea - I can point to it! You can say "The nature around us", because qualifying "nature" with "around us" makes it definite, just as "tea" (indefinite) can become "the tea in my cup". No, "some" and "there are" are in no way informal; they are not redundant and certainly not wrong. "Somehow" is an adverb so not relevant here. I don't see why "there are" would require "some", unless you desire to emphasise that aspect. // You're right that some of this is philosophy, but that doesn't make it optional. Each language has an associated philosophy...

... and when learning a language you need to learn its associated philosophy. The choices are in a sense arbitrary, in that each language may choose differently: for example, with regard to definiteness, English treats proper nouns as "obviously definite", and so no article is used at all ("Fred"); in Greek proper nouns take a definite article ("The Fred"); in Arabic the proper noun itself doesn't generally take an article, but any adjective agreeing with it does ("The-tall Fred")...

...But just because they're somewhat arbitrary doesn't mean they don't need to be learnt, just as irregular verbs must be - if you start saying things like "I like the nature", people won't think "He's got a different philosophy of language", they will think "He is bad at English".