Final answer:
Madame Defarge in 'A Tale of Two Cities' shows her merciless strength through her relentless commitment to vengeance, embodying the violent revolution without empathy. Her ruthless nature is typified in her determination to punish enemies and her portrayal as physically intimidating and resolute.
Step-by-step explanation:
Madame Defarge, a character from Charles Dickens' novel A Tale of Two Cities, exhibits her merciless strength through her unwavering commitment to the revolutionary cause and her ability to inspire fear. Her harshness is not just the result of personal grievances but also stems from the collective suffering of her comrades.
Through interactions with other characters, Madame Defarge's ruthless personality is illustrated by her lack of empathy and her determination to see her enemies meet with justice, as per her own definition.
Her role in the narrative is critical as she embodies the aspect of the revolution that is violent and unforgiving. Madame Defarge shows her relentlessness as she knits a registry of names of those whom she believes must pay for their sins against the people.
She demonstrates physical strength in various instances, for example, by showing she's capable of exerting force when needed, depicted in one of the quoted texts where a character throws down goods in a wild manner.
Likewise, the descriptions of other characters, like Jane Withersteen, who also show a form of indomitable spirit, albeit in different contexts, reflect on the thematic exploration of resilience and conviction.