Through some of my favorite chapters, titled "Nature and Wonder: A Reconnaissance of Heaven," "The Organic Universe," "Extraterrestrial Intelligence," and "The God Hypothesis" he takes us on a journey through the universe and evolution and shows us the lack of evidence for the existence of God, the way God is defined in western religions. In his Q&A at the end of the book, he states, "And I hope it is clear that the fact that I do not see evidence of such a God's existence does not mean that I then derive from that fact that I know that God does not exist. That's quite a different remark. Absence of evidence is not evidence of absence. Neither is it evidence of presence." As I teach on the first day of my science class, "Is there a God?" is not a scientific hypothesis because it does not follow the principle of falsifiability. It cannot be proven wrong, so it is not a valid question to ask in the sciences. There's no experiment for "Is there a God?" so it's not a place for science. Having said that, there is also no evidence that God exists and it takes a leap of faith to believe in something with no proof of existence.
"Since the times are so extraordinary (spoken in 1985), since they are unprecedented, it is in no way clear that ancient prescriptions retain perfect validity today. That means that we must have a willingness to consider a wide variety of new alternatives, some of which have never been thought of before, others of which have, but have been summarily rejected by one culture or another. We run the danger of fighting to the death on ideological pretexts (much of his book worries about nuclear war).A great quotable on natural selection:
We kill each other, or threaten to kill each other, in part, I think, because we are afraid we might not ourselves know the truth, that someone else with a different doctrine might have a closer approximation to the truth. Our history is in part a battle to the death of inadequate myths.
'If I can't convince you, I must kill you. That will change your mind. You are a threat to my version of the truth. The thought that I may have dedicated my life to a lie, that I might have accepted a conventional wisdom that is no longer, if it ever did, corresponds to the external reality that is a very painful realization. I will tend to resist it to the last. I will go to almost any lengths to prevent myself from seeing that the worldview that I have dedicated my life to is inadequate.'
I'm trying to describe a psychological dynamic that I think exists, and it's important and worrisome!
Instead of this, what we need is a honing of the skills of explication, of dialogue, of what used to be called logic and rhetoric and what used to be essential to every college education, a honing of the skills of compassion, which, just like intellectual abilities, need practice to be perfected. If we are to understand another's belief, then we must also understand the deficiencies and inadequacies of our own. And those deficiencies and inadequacies are very major. This is true whichever political or ideological or ethnic or cultural tradition we come from. In a complex universe, in a society undergoing unprecedented change, how can we find the truth if we are not willing to question everything and to give a fair hearing to everything? There is a worldwide closed-mindedness that imperils the species. It was always with us, but the risks weren't as grave, because weapons of mass destruction were not then available. Why is there not a commandment exhorting us to learn? "Thou shalt understand the world. Figure things out." Very few religions urge us to enhance our understanding of the natural world. I think it is striking how poorly religions, by and large, have accommodated to the truths that have emerged in the last few centuries.
Let's think together for a moment about the prevailing scientific wisdom on where we come from. (Knowing that he said this when I was 3 years old and 26 years later, people still are denying this makes me very, very depressed.). The idea that nearly 15,000 million years ago the universe, or at least its present incarnation, was formed in the big bang, that for some 5,000 million years thereafter even the Milky Way Galaxy was not formed; that for some 5,000 million years after that the Sun and the planets and the Earth were not formed; that 5,000 million years ago, on an Earth not identical by any means to the one we know today, a large-scale production of complex organic molecules occurred that led to a molecular system capable of self replication, and therefore began the long, tortuous, and exquisitely beautiful evolutionary sequence that led from those first organisms, barely able to make vague copies of themselves, to the magnificent diversity and subtlety of life that graces our small planet today.
I think if we ever reach the point where we think we thoroughly understand who we are and where we came from, we will have failed. I think this search does not lead to a complacent satisfaction that we know the answer, not an arrogant sense that the answer is before us and we need do only one more experiment to find it out. It goes with a courageous intent to greet the universe as it really is, not to foist our emotional predispositions on it but to courageously accept what our explorations tell us."
"Many animals have codes of behavior. Altruism, incest taboos, compassion for the young, you find in all sorts of animals. Nile crocodiles carry their eggs in their mouths for enormous distances to protect the young. They could make omelet out of it, but they choose not to do so. Why not? Because those crocodiles who enjoy eating the eggs of their young leave no offspring. And after a while all you have is crocodiles who know how to take care of the young. It is very easy to see. And yet we have a sense of thinking of that as being somehow ethical behavior. I'm not against taking care of children; I'm strongly for it. All I'm saying is, it does not follow if we are powerfully motivated to take care of our young or the young of everybody on the planet, that God made us do it. Natural selection can make us do it, and almost surely has."
On using God to explain what we don't yet understand
"Both in classic and in medieval times, it was prominently speculated that gods or angels propelled the planets, gave them a twirl every now and then. The Newtonian gravitational superstructure replaced angels with GMm/r^2 (my students always forget to square this), which is a little more abstract. And in the course of that transformation, the gods and angels were relegated to more remote times and more distant causality skeins. The history of science in the last five centuries has done that repeatedly, a lot of walking away from divine microintervention in early affairs.
So as science advances, there seems to be less and less for God to do. It's a big universe, of course, so He, She, or It could be profitably employed in many places. But what has clearly been happening is that evolving before our eyes has been a God of the Gaps; that is, whatever it is we cannot explain lately is attributed to God. And then after a while, we explain it, and so that's no longer God's realm. The theologians give that one up and it walks over to the science side of the duty roster."
"Suppose your father walked into this room at the ordinary human pace of walking. And suppose just behind him was his father and just behind him was his father. How long would we have to wait before the ancestor who enters the now-open door is a creature who normally walked on all fours? The answer is a week. Our quadruped ancestors are, after all, only tens of millions of years ago, and that's 1% of geologic time."