In 'The Second Sex', Simone de Beauvoir explores the complex identity of women and the societal constructs that define femininity, challenging the notion of women as mere 'others' in relation to men. She argues that women have been historically subordinated and lack a collective identity or solidarity that can empower them, leading to a perception of themselves as inessential. The text critiques the idea of 'eternal femininity' and calls into question the essentialist views of gender, urging a reevaluation of women's roles in society.