Il est vs. C'est with nouns plus adjectives : Bien qu'il soit actuellement l'astronaute français le plus célèbre...

Question

Why is it "Bien qu'il soit actuellement l'astronaute français le plus célèbre...", and not "Bien que ce soit actuellement l'astronaute français le plus célèbre..." ? I thought that you have to use "c'est" (and not "il est") with a noun that has an article and an adjective.

Accepted Answer

Hi Clarence, 
As you say in your second comment it is a kind of variation to the rule. Not so much an exception as you could also say -
Bien que ce soit actuellement l'astronaute français le plus célèbre ...
but that would make it a general statement and the use of 'il' puts emphasis on the person you are talking about.
We get so many mistakes regarding the kind of sentences like - He is my brother, he is my daughter's teacher, he's my cat  etc.

C'est ( never - il est )mon frère = He is my brother
C'est ( not il/elle est ) mon chat = He's my cat 
C'est ( not il/elle est)  le professeur de ma fille = He is my daughter's teacher 
C'est Maria ( not elle est Maria) = This is Maria 
C'est Monsieur Martin  ( not il est Monsieur Martin) = This is Mr Martin

That it is safer to use 'c'est' when followed by a name or a noun.
Occasionally, I have noticed in novels, sentences which contradict the rule like - 
Elle est ma fille ! = She is my daughter (after all)
It stresses the fact that she should behave like a daughter.
Also in the case of superlatives as in this example, you will use il or elle to emphasize the importance of the person -

Elle est l'actrice française la plus connue dans le monde entier = She is the most famous French actress in the whole world 
Il est le meilleur ! = He is the best !

Hope this helps!

Answer

Bien qu'il soit astronaut... -- Although he is an astronaut...In this sentence, c'est is not possible because that would mean "even though that's an astronaut."

Answer

Oh, I thought "c'est" was obligatory here as explained in Rule 1 on this page: "C'est" vs "Il/Elle est" to say it is/she is/he is in French : "If it/he/she is is followed by un/une/le/la... (any form of article / determinant) - it is a beautiful dress / she is a nice person - then you will use c'est."

Is there something about the description "le plus célèbre" that makes this an exception to the rule, so that you have to use "il est"?

Answer

I know this can be difficult to grasp and develop a feel for. In this case, you are referring to a specific person and you're making a specific statement about him. Referring to the exercise in your link, I would call this a case of rule 2b.