defeat of the weaker; survival of the fittest
Often used in the context of social Darwinism or competitive selection, where the inferior or weaker side is eliminated. Frequently appears in the compound 優勝劣敗 (yūshō reppai).
自然界では優勝劣敗が原則だ。
In nature, the principle is the survival of the fittest.
資本主義の下
Some people think that under capitalism, the defeat of the weaker is inevitable.
survival of the fittest
Compound of 劣 (retsu, 'inferior') and 敗 (hai, 'defeat'). The reading れっぱい results from the assimilation of れつ + はい.