Final answer:
In 1945, Simone de Beauvoir and Jean-Paul Sartre founded 'Les Temps Modernes,' with de Beauvoir known for her existential philosophy and feminist work, notably 'The Second Sex.'
Step-by-step explanation:
In 1945, Simone de Beauvoir and Jean-Paul Sartre founded a monthly review called Les Temps Modernes. Simone de Beauvoir challenged the traditional social norms and is renowned for her significant contributions to existentialist philosophy and feminism. Her lifelong partnership with Sartre involved intense intellectual collaboration and editing each other's work, which included establishing the influential journal Les Temps Modernes together. Her groundbreaking work, The Second Sex, is a testament to her intellectual rigor and her quest to dissect and dismantle the then prevailing social constructs surrounding women's roles in society.