egoism; self-love
A philosophical term referring to the ethical stance that self-interest is the foundation of morality, or the tendency to prioritize oneself. Often used in discussions of ethics and psychology.
Egoism is discussed as a concept opposed to altruism.
His actions seem to be based on egoism.
利他主義 (altruism) is the direct opposite of 主我主義, prioritizing others' welfare over one's own.
Compound of 主我 (shuga, 'ego' or 'self as the primary concern') and 主義 (shugi, '-ism'). The exact historical derivation is uncertain, but it follows the pattern of many Meiji-era philosophical coinages.