"The first pillar is the concept of Dubai as a global and multicultural city, one that doesn't discriminate about whom to welcome." Dubai: The Making of a Megapolis by Pranay Gupte Why do we have to add "one" in the appositive clause? Is "The first pillar is the concept of Dubai as a global and multicultural city that doesn't discriminate..." correct English? I have the impression one must add "one" but why? Is the original a relative clause? If yes, shouldn't we have "one which" in an appositional relative clause? Thanks.
"one" is needed in the apposition because appositions are, by definition, nominal (i.e. they have to contain a noun head).
As "one" refers to "a global and multicultural city," it can take a relative clause starting with that or which. If "one" were not there, instead of an apposition we'd have a non-restrictive or non-defining relative clause, and only "which" would be allowed.
I agree with Clare's comment that using a relative clause or an apposition containing a relative clause is only a matter of style. What is clear is that, with the relative clause being restrictive or defining in both cases, the meaning seems to be -- according to grammar rules -- that not all global and multicultural cities don't discriminate about whom to welcome -- Dubai is one that does not, but there might be others that do.
However, in practice the meaning is closer to:
- The first pillar is the concept of Dubai as a city that, being global and multicultural, does not discriminate about whom to welcome.