My very favorite point in William James' "A Pluralistic Universe" can serve to justify one of his main points here:
Our intelligence cannot wall itself up alive, like a pupa in a chrysalis. It must at any cost keep on speaking terms with the universe that engendered it.
This encapsulates James' thoughts on the importance of experience which is summed up in this essay in addition to his Essays in Radical Empiricism. While the latter work sets up the structure of the philosophy of William James, it is "A Pluralistic Universe" that exhibits James' conclusions on the subject of "pure experience" and that philosophy of experience that James feels is so important to life.
It is important to note that critics become disillusioned with James in the final moments of "A Pluralistic Universe" because they feel, by giving opposing opinions, he destroys all of his previous concepts that he explored in Essays in Radical Empiricism and that he explored earlier in this particular essay.
However, it's important also to note that subscribers to James' full account of philosophical thought believe this essay to be VERY important. These subscribers say that "A Pluralistic Universe" is absolutely necessary for understanding James' philosophical view in its entirety. These people also agree that it is one of the absolute best critiques of Hegel's dialectical method, which is another main point of James' essay.