It is something else that he provides.

From Thackeray they are expected,--and from many others.

But Thackeray never disappoints.

Whether it be a great duke, such as he who was to have married Beatrix, or a mean chaplain, such as Tusher, or Captain Steele the humorist, they talk,--not as they would have talked probably, of which I am no judge,--but as we feel that they might have talked.

We find ourselves willing to take it as proved because it is there, which is the strongest possible evidence of the realistic capacity of the writer.
As to the sublime in novels, it is not to be supposed that any very high rank of sublimity is required to put such works within the pale of that definition.