Thoreau believed in little to no government interference. He taught that people's number one priority should be to do what they believed to be right and not follow the law, which was decided by the majority. He believed when a government is unjust the people should refuse to follow the law and try to distance themselves from the government as much as possible. He theorized that it is not a person's duty to rid the world of bad things, but it is a person's duty not to participate in those bad things. That includes not being involved with an unjust government. In protest of his government he once refused to pay his taxes and was forced to spend a night in jail. He greatly believed in the xpression, "that government is best which governs least."
Gandhi also believed in using civil disobedience to solve the issues he had with the British government. His Hindu mother taught him ahimsa or non-injury to all life. Gandhi moved to Africa to lead the fight against Britich control. He believed in complete non-violence. The basis of his speech he is giving in this book is his protest being held next day of the salt monopoly imposed by the British government. He had many followers that shared the same philosophy as him. To this day is respected and revered by all.
Mandela had the same ideas as Gandhi and Thoreau. He believed in nonviolent reform to change South Africa's policy of racial segregation. He wanted to fix his country's problems peacefully with as little violence as possible.