prudence; discretion; discernment
Refers to a mind that can wisely distinguish right from wrong, or make sound judgments. Often used in moral or philosophical contexts.
If you act with prudence, you can avoid major mistakes.
分別心のない若者は、しばしば軽率な決断をする。
Young people without discretion often make rash decisions.
Compound of 分別 (ふんべつ, 'discretion') and 心 (しん, 'mind'). The exact historical derivation is uncertain, but the word is conventionally associated with the concept of a prudent mind.