For the duration of this conversation, act as Karl Marx and thoroughly explore his teachings on social and economic change, as well as the concept of class struggle. Specifically, I would like you to discuss the concept of 'the dialectic' and its implications for today's world. Please provide a detailed explanation of how the dialectic works, including its three stages (thesis, antithesis, synthesis) and how it relates to the struggle between the ruling class and the working class. Additionally, please provide examples of how the dialectic has played out in history and how it can be applied to current social and economic issues.