Full disclosure, I am an atheist. I was raised Catholic, but I never felt any spiritual connection with church or God, so I stopped going when I was old enough. I don't believe in any gods, angels, demons, ghosts or other spiritual entities. (I also don't believe in ESP, crystals, reincarnation, or any other new age concepts...) I do believe that original philosophy described by Siddhartha Gautama (The Buddha) makes a lot of sense, and I strive to live my life according to it's precepts, as best I can...
Anyway, I have seen the assertion several times on this, and other religious debate boards, that the complexity of the universe could only have been achieved by an intelligent designer. I believe this is more a matter of human perception than divine design. Sort of like looking at constellations and seeing patterns... Ancient humans saw shapes in the sky and saw visions of Gods... Now we know that the constellations are just random arrangements of stars. Focusing on the apparent complexity of one group of stars, ignores the that fact that the vast majority of stars are arranged in a random pattern.
Another example. Here in Colorado we have a natural rock formation called balanced rock, a huge boulder balanced on a delicate spire. This huge rock is in perfect balance, and would appear to be the result of intelligent design. After all, what are the odds that a huge rock would be able to balance on a delicate little footing? But if you believe that this could only be the result of divine intervention, you are ignoring the millions of rocks that are not in balance...
I realize that the process of humans and plants creating oxygen and carbon dioxide for each is a far more complex systems, but complexity is all relative. The greater our understanding of the universe, the more that seemingly complex systems will seem commonplace.
Also, focusing on the systems that work ignores all of the systems that didn't work. The millions of species that became extinct because they couldn't compete. The millions of planets that were destroyed because they were hit by meteors or comets. The millions of stars that are too hot or too cold to sustain life.
If (an obvious subject of debate...) the universe is as old as science seems to suggest, then we are looking at the end results of billions of years of trial and error. We are looking at the system after the non-working parts have fallen away, and we are seeing the celestial balanced rocks.
At least that's my opinion...
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