Who is Soseki's Brother from Kokoro and what is their importance?

Older than Soseki by unmentioned years, Soseki's elder brother is already ensconced in his career in another province. Since his arrival, Soseki's brother feigns positivism in front of their parents but believes their father is in a more advanced state than he is. It is apparent he upsets Soseki when he opines that their father may not understand what he reads in the paper. Though Soseki worries himself, he asserts their father is still able to understand. Though never particularly close to his elder brother, Soseki momentarily bonds with him over a conversation about their family. Their connection is quickly lost however, when Soseki's brother asks him to stay on at the house when their father passes away. Though Soseki believes his brother should, as the eldest, take his father's place, his brother sees the option as impossible as he has already established a lifestyle and career elsewhere.