The word "should" can be very subjective, because it implies judgment and/or opinion -- yet the 2nd half of Rubin's quote sounds like everything is preordained. This reminds me of Billy Pilgrim in Vonnegut's Slaughterhouse Five. He could visit any time in his life, but was powerless to change it.
And yet, "to change tomorrow for the better" requires a "conscious" decision in the "amazing process of human evolution." Which, when I really think about it, is as it should be or must be.
Perhaps wisdom can be found in what seems to be a contradiction but really isn't.
To a professor of earth science the written history of mankind is but a fleeting moment in the geologic record, yet an intense moment in one's life can feel like an eternity and be remembered in oral history passed from one generation to many that follow.
Both are true. It is up to each one of us to understand the broader context in our own conscious evolutionary path which, collectively, can chart a course for a better future.
Which brings us to the present, where we all live (except the occasional mystic or Billy Pilgrim).