What are two ways in which philosophes sought to change the world?

It's possible through observation to interpret how we think, but to philosophize about it is rather pointless because it changes nothing. I think Karl Marx is trying to say here that knowledge only goes so far. Generations of philosophers have gained knowledge off of each other and themselves, but it comes down to personal change in how we think and view the world. We are all one in one reality but your world is different from say mine or Karl Marx's. Whenever philosophers interpret they use thought of what they know, and say they know. How ridiculous! Is that truth? Einstein realized after many hypothesis that you only end up with more hypothesis. The amount to know is infinite and we try to compare that to the infinity of the mind. Thought is limited and when that is realized on a global scale there will be change. I agree completely with Karl Marx, though I'm interpreting him through what I know, which may not be truth.