one's nature; one's disposition
Rare literary noun referring to a person's inherent character or temperament. In modern Japanese, 性質 or 性格 are far more common.
His nature is gentle, and he quickly gets along with anyone.
gentle disposition; mild character
upright character; noble nature
wise and clear-sighted; intelligent and astute by nature
The exact derivation is uncertain; the kanji 資 (resources, nature) and 性 (nature, character) combine to suggest innate disposition. The word is not commonly used in modern Japanese.