Murray, please don't take the following as a personal attack since I am responding to your post. It is a refutation of a way of thinking that IMO is easily refuted....
There are many other world views, some of which do not require a supernatural being.
However, rejection of the existence of reality outside what one's senses can detect, a.k.a. the supernatural, results in complete intellectual incoherence. Humanism is a perfect example. While much in their Affirmation represents orthodox Judeo-Christian thinking and so is hard to argue with, the balance is illogical gibberish. For example, you'd be hard pressed to find a Christian who disagreed with this tenant:
We believe that scientific discovery and technology can contribute to the betterment of human life. Of course that is correct. Now, you might find the odd member of a marginal Christian or Judaic sect who disagrees I suppose, but then again, you'll find humanists who think that marrying trees is coherent thinking. Rather than pointing out all the areas of the Affirmation that are standard Christian thinking, here's where their assertions begin to break down, logic-wise:
We deplore efforts to denigrate human intelligence, to seek to explain the world in supernatural terms, and to look outside nature for salvation.
So, right after affirming the value of scientific exploration and stating their opposition to the denigration of human intelligence, the Humanist dismisses, deplores and marks as off limits the consideration of the existence of the supernatural, that is, things outside this natural world. Human intelligence and scientific exploration don't advance when dogmatists insist that explanations they find "deplorable" cannot be explored. Very confused thinking here.
We believe in the cultivation of moral excellence.
It invariably happens that out of one side of their mouths Humanists deny the existence of objective morality that would require the supernatural (since it exists whether the natural world exists or not), and out of the other side say they value things like "moral excellence". Without the existence of objective morality that exists supernaturally, talking about morality becomes a purely subjective thing. If subjective, then what is one man's moral excellence (sanctity of the person), becomes another man's immoral behavior (refusal to allow your daughter to have a forced clitorectomy.) In Hitler's mind, he was completely moral. In other words, if the only morality that exists is local and subjective, then the concept of any moral standard that binds human behavior is complete gibberish, yet that is what Humanists insist they believe in
We respect the right to privacy. Mature adults should be allowed to fulfill their aspirations, to express their sexual preferences, to exercise reproductive freedom, to have access to comprehensive and informed health-care, and to die with dignity.
More gibberish. I presume most Humanists would say that raping babies, even if the mature adult doing so is fulfilling their aspirations is bad, they have no reason to do so since they reject objective standards of good of evil. I gather this is also a shout out to abortion, which kills a human being. How do you square the circle of being for the protection of the innocent as the Humanist says they are, while condoning killing them?
We believe in the common moral decencies: altruism, integrity, honesty, truthfulness, responsibility. Humanist ethics is amenable to critical, rational guidance. There are normative standards that we discover together. Moral principles are tested by their consequences.
We are deeply concerned with the moral education of our children. We want to nourish reason and compassion.
Gibberish squared. Absent an objective standard of what is good and what is evil, the concepts of altruism, honesty, responsibility are whatever a local population deems them to be, so these terms are meaningless in the Humanist context.
We are skeptical of untested claims to knowledge, and we are open to novel ideas and seek new departures in our thinking.
Totally dishonest. The Humanist is not open to seeking new departures in their thinking, since they dogmatic reject the existence of that which they "deplore". Further, kindly show the "test" that proves Humanism. It doesn't exist, since Humanism is so full of logical contradictions regarding morality, so how can they say they are "skeptical" of the behavior that is at the very core of their belief system?
We believe in optimism rather than pessimism, hope rather than despair, learning in the place of dogma, Unless the dogma contradicts our insistence that the supernatural doesn't exist, in the which case, that dogma is just fine....
truth instead of ignorance, joy rather than guilt or sin, Whose "truth" would that be, since absent objective Truth, truth is whatever floats your boat, and where does the concept of sin come from since that also presumes the existence of that which the Humanist rejects - something one could sin against?...
tolerance in the place of fear, love instead of hatred, compassion over selfishness, beauty instead of ugliness, and reason rather than blind faith or irrationality. ….unless, reason leads one to conclude that a Creator must exist since life can't organize itself, nor Nothing produce a Universe filled with something.
We believe in the fullest realization of the best and noblest that we are capable of as human beings.
Since the Humanist rejects objective standards of behavior, the ideas of "nobility" or "best" are gibberish. Joseph Stalin rose from humble beginnings to save his nation. I doubt he could have risen higher in the world of accomplishments. True, he murdered tens of millions, but if there are no objective standards of behavior, who is to say he wasn't the very epitome of achieving this Humanist aspiration?
Bottom line - when you reject the existence of objective good and objective evil that stands outside the natural world, you lose all standing to say anything about what is "good" or "evil". You can only say you prefer behaving like "x" vs. "y", even if you are incapable of providing the slightest reason why such a choice has the slightest merit. Humanism is a self-defeating logic, which is why it is so easy to argue against. It argues against itself better than I could.