The quote "Kindness is stronger than iron bars" from the book "Mary Queen of Scotland and The Isles" by Margaret George suggests that compassion and empathy hold greater power than physical barriers or restraints. It emphasizes the impact of kindness not only on personal relationships but also on overcoming challenges and adversity.

This statement reflects the theme that human connections and the ability to show love and understanding can transcend limitations imposed by society or circumstances. Ultimately, it highlights the enduring strength of kindness as a force for positive change in the world.