I do think that the definition of Liberalism quoted in this article is weird--although a Liberal society will necessarily have a democratic political process, and that can be a vehicle for nonviolent social change. At the same time, 'open-mindedness' is a trait that was once associated with Liberalism.

The narrow political ideologies that have developed within Liberalism (libertarianism, conservatism, liberalism, and democratic socialism) have caused thinking about society--its problems and possible solutions for them--to become ossified. What is most needed, I think, is a willingness as a society to promote the development of new ideas and their dissemination. For starters, people need to drop all of those political ideologies and become Liberals.