自し然ぜんの勢いきおい

expression, noun

natural tendency; natural course of events; force of circumstances

Refers to the way things naturally unfold without external intervention; often used when events proceed according to their own momentum or inherent logic.

• 自し然ぜんの勢いきおいで、彼かれはリーダーになった。

  By the natural course of events, he became the leader.

• 物もの事ごとは自し然ぜんの勢いきおいに任まかせるのが一いち番ばんだ。

  It's best to let things take their natural course.