I suppose suppose it could be said that the second item in the list of the six mentioned in the Humanist Manifesto 3 is an extension of the first. In full, this item reads “Humans are an integral part of nature, the result of evolutionary change, an unguided process.” If you remember that first item, it had to do with empiricism, including observation, experimentation, and rational analysis. You know, the scientific method, critical thinking, pragmatism, etc.
However, this item is a bit more specific. Rather than simply invoking the scientific example, it provides an important (and still controversial) example: Evolution. It also goes much further, stating that mankind is a part of nature, not in some way set apart. Human beings started their existence as more-than-amoebae but less-than-fish, and have evolved into what we are today, homo sapiens, via the trial and error of nature’s largest scientific experiment, evolution.
It is difficult to judge which of these concepts is more important. In my opinion, it is critical that humans see themselves as simply a part of the greater mosaic of nature. In my own case, I have expanded nature from that known to us on our one little planet to that which exists everywhere in the universe. That tends to give me an idea of scale, and informs me of where I fit in our grand puzzle.
I am a short-lived bit of protoplasm, existing for a mere twinkling and dwelling in a tiny cosmic backwater known as Earth, at least to the locals. I have importance only to those immediately around me; with that comes a responsibility to help wherever I can, to learn everything that I can, and further to understand all that I can, with all the connections and fine structure which that entails. I don’t have much time.
My connectedness to nature and the universe is exemplified by having been through the complex filter of evolution. I am not now what my ancestors once were. Humans tend to think of themselves as the highest form of being on the planet; that remains to be seen. Clearly, though, we have gained critical facilities during our journey from the swamp to civilization. Again, whatever elevated position we have reached in the hierarchy of nature through the grand scientific experiment of evolution should bring us to the same realization about responsibilities that is mentioned above.
We don’t need a magic, mythical god-figure in the sky. Nature, and our part in it, is much more complex and beautiful than any religion yet invented. If we could all just celebrate the beautiful things that actually are, without resorting to fantasy and superstition, we could all simply get on with making our small part of the universe the best that it can be.