Human Nature, Instinct
noun
A person's nature is just human nature! Everyone has their own human instincts.
じんせい
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
私は、大学で人性学を勉強しています。
I'm learning ethology at university.
私は、キリストは神性と人性という二つの本性を持つという両性せつを支持します。
I support the dyophysite that Jesus has two natures: a divine nature and a human nature.
人性論における人間の本性において、私は結局人の性質は善悪を共に備えていると思います。
With regard to the discussion about original human nature in Confucianism, I believe that human nature is equipped with both good and evil sides after all.