inborn nature; innate disposition
A formal, somewhat literary term for one's inherent character or temperament. Rare in everyday conversation; more common in philosophical or psychological contexts.
His gentle manner comes from his inborn nature.
Education is important, but it is difficult to change one's innate disposition.
From Chinese 稟性 (bǐngxìng), meaning 'natural disposition'. The exact historical derivation is uncertain, but the kanji 稟 suggests something received or endowed, and 性 means nature or character.