I think that Stallybrass means that all knowledge builds on itself. I think he means that our thoughts should be compilations of what we have learned from other people, or taking what we have learned from others and thinking about it in a new way. Also, he points out good ideas don’t spontaneously appear in our heads, they are formed from actively researching a topic. One can spend hours thinking in circles, but come to no conclusions if they don’t have a base to work off of and a process to go about it. I think he means that in order to have a “new idea” one has to organize bits and pieces of many peoples knowledge in a clear way