Final answer:
Mary Wollstonecraft, an English philosopher and advocate of women's rights, argued that the emancipation of women would lead to a more equitable society, with women having equal educational and intellectual opportunities. Her influential work, 'A Vindication of the Rights of Woman', challenged the existing social order and proposed an alternative founded on reason.
Step-by-step explanation:
Mary Wollstonecraft was a seminal English thinker and advocate of women's rights during the Enlightenment. In her groundbreaking work A Vindication of the Rights of Woman, Wollstonecraft argued for the emancipation of women, suggesting that their apparent inferiority was due to a lack of education rather than inherent weakness. She envisioned an empowered role for women in a rational social order founded on reason.
When considering the emancipation of women, Wollstonecraft believed it would result in a more equitable society where women could contribute to social progression by engaging in educated discourse and decision-making processes, no longer being constrained by lack of access to education and, thus, intellectual development.
Regarding the custom in Russia involving son-in-laws, Wollstonecraft held critical views on various social customs and their impacts on women's lives. However, specifics on her thoughts about this Russian custom are not detailed in the reference materials provided. Her broader arguments, though, are often rooted in the philosophy that women are unfairly limited by societal norms and should have equal rights and opportunities.