I agree with Hurkyl, your confusing the two. I'm not saying capitalism doesn't have its benefits for scientific research, but to say that it is necessary is wrong. What do you define as Science? What about the origins of Science? The things that required inclined planes, rolling balls, and a mind? Why do you need capitalism there? You may need industry and interest from people in high political places, but not capitalism. What about the Soviet Union? are we discrediting the soviet scientific endeavor because of its lack of capitalism? The USSR has many discoveries and kept up with us. What about China? What about other non free-market economies like state-controlled Nazi Germany? There science was pretty advanced. It may have been more fractionalized and difficult, but if you could convince the political leaders that your research was beneficial to the state, then you were granted the ability to do research.