"I love tea, but I adore coffee."
Translation:J'aime le thé, mais j'adore le café.
This only applies to things that can't be count. You can't say : I have four tea or I have ten coffee. It doesn't make sens. For these word you can say "le thé" while talking about tea in general since you can't have a tea. So when you use "le" in these situations you are talking about all the tea or all the coffee that exists. When using "du" you are talking about a portion of all the tea. For exemple, you can say : I have tea ("J'ai du thé"). You can't have all the tea in the world but you can have a small portion of all the tea that exists. So using "du" means exactly that. If you want to say that you love only some kind of tea and not all of it you would not say "J'aime du thé". This doesn't sound right and is not precise enough anyway. You could say "J'aime le thé anglais" for exemple.
le/ la/ les = the = specific =that/ those one/s right there. eg: I like the wine (on the table)
du = some = but not all. eg:I like some wine (but not all wine)
le/ la/ les = general = all. I like all the wine (that I have ever seen or heard of) =all examples of something or all members of a group or community.
In English we just drop the article to express generality. eg: I like wine = I like all wine. But in French you can't just drop the article. You have to have a modifier for most nouns. Rather than invent a new article to express generality, they assigned that role to le/ la/ les.
J'aime le thé means either I like the tea (right there) or I like all tea. In the example we are given here he seems to be speaking generally. So it's J'aime le thé because that's how generality is expressed.
J'aime les enfants = I like the children = those ones, the ones we were talking about previously.
J'aime des enfants = I like (some) children = but not all of them.
J'aime les enfants = I like the children = all the children in the world, or all the children in the class, or all the children present etc.= all examples of something
Context tells you which use is appropriate. Je bois le vin = I drink the wine (that wine right there). It can't mean all the wine in the world because you can't drink all the wine in the world. You can like all the wine or children in the world but you can't drink it all or talk to them all .
There is no comparable use of such an article in English. You just have to remember that in French there is an extra usage of the article le/ la/ les that appears on a regular basis.
Edit: ...Sitesurf has reminded me in other posts that like is an appreciation verb and therefore in French cannot be limited to some. You either like the wine that we know about or you like all wine. If you want to say you like some wine you have to use another more action type of verb such as ...I like to drink some wine, I like to taste some wine etc.