The Varieties of Scientific Experience: A Personal View of the Search for God

in the segregated South of 1962, at demonstrations of nonviolent civil disobedience, on the Tonight show. And he did this while maintaining a pioneering, astonishingly productive, fearlessly interdisciplinary scientific career.

He was especially thrilled to be invited to give the Gifford Lectures on Natural Theology of 1985 at the University of Glasgow. He would be following in the footsteps of some of the greatest scientists and philosophers of the last hundred years- including James Frazer, Arthur Eddington, Werner Heisenberg, Niels Bohr, Alfred North Whitehead, Albert Schweitzer, and Hannah Arendt.

Carl saw these lectures as a chance to set down in detail his understanding of the relationship between religion and science and something of his own search to understand the nature of the sacred. In the course of them, he touches on several themes that he had written about elsewhere; however, what follows is the definitive statement of what he took pains to stress were only his personal views on this endlessly fascinating subject.

At the beginning of each Gifford Lecture, a distinguished member of the university community would introduce Carl and marvel at the need for still more additional halls to accommodate the overflow audience. I have been careful not to change the meaning of anything Carl said, but I have taken the liberty of editing out those gracious introductory remarks as well as the hundred or more notations on the audio transcripts that merely say '[Laughter].'

I ask the reader to keep in mind at all times that any deficiencies of this book are my responsibility and not Carl's. Despite the fact that the unedited transcripts reveal a man who spoke extemporaneously in nearly perfect paragraphs, a collection of lectures is not exactly the same thing as a book. This is especially true when the Pulitzer Prize-winning author in question never published anything without combing at least twenty or twenty-five iterations of every manuscript for error or stylistic infelicity.

There was plenty of laughter during these lectures, but also the kind of pin-drop silence that comes when the audience and the speaker are united in the thrall of an idea. The extended dialogues in some of the question-and- answer periods capture a sense of what it was like to explore a question with Carl. I attended every lecture, and more than twenty years later what remains with me was his extraordinary combination of principled, crystal-clear advocacy coupled with respect and tenderness toward those who did not share his views.

The American psychologist and philosopher William James gave the Gifford Lectures in the first years of the twentieth century. He later turned them into an extraordinarily influential book entitled The Varieties of Religious Experience, which remains in print till this day. Carl admired James's definition of religion as a 'feeling of being at home in the Universe,' quoting it at the conclusion of Pale Blue Dot, his vision of the human future in space. The title of the book you hold in your hands is a tip of the hat to the illustrious tradition of the Gifford Lectures. My variation on James's title is intended to convey that science opens the way to levels of consciousness that are otherwise inaccessible to us; that, contrary to our cultural bias, the only gratification that science denies to us is deception. I hope it also honors the breadth of searching and the richness of insight that distinguished Carl Sagan's indivisible life and work. The varieties of his scientific experience were exemplified by oneness, humility, community, wonder, love, courage, remembrance, openness, and compassion.

In that same drawer where the transcript of these lectures was rediscovered, there was a sheaf of notes intended for a book we never had the chance to write. Its working title was Ethos, and it would have been our attempt to synthesize the spiritual perspectives we derived from the revelations of science. We collected filing cabinets' worth of notes and references on the subject. Among them was a quotation Carl had excerpted from Gottfried Wilhelm Leibniz (1646-1716), the mathematical and philosophical genius, who had invented differential and integral calculus independently of Isaac Newton. Leibniz argued that God should be the wall that stopped all further questioning, as he famously wrote in this passage from Principles of Nature and Grace:

'Why does something exist rather than nothing? For 'nothing' is simpler than 'something.' Now this sufficient reason for the existence of the universe… which has no need of any other reason… must be a necessary being, else we should not have a sufficient reason with which we could stop.'

And just beneath the typed quote, three small handwritten words in red pen, a message from Carl to Leibniz and to us: 'So don't stop.'

• Ann Druyan Ithaca, New York March 21, 2006

Author's Introduction

In these lectures I would like, following the wording of the Gifford Trust, to tell you something of my views on what at least used to be called natural theology, which, as I understand it, is everything about the world not supplied by revelation. This is a very large subject, and I will necessarily have to pick and choose topics. I want to stress that what I will be saying are my own personal views on this boundary area between science and religion. The amount that has been written on the subject is enormous, certainly more than 10 million pages, or roughly 10¹¹ bits of information. That's a very low lower limit. And nevertheless no one can claim to have read even a tiny fraction of that body of literature or even a representative fraction. So it is only in the hope that much that has been written is unnecessary to be read that one can approach the subject at all. I'm aware of many limitations in the depth and breadth of my own understanding of both subjects, and so ask your indulgence. Fortunately, there was a question period after each of the Gifford Lectures, in which the more egregious of my errors could be pointed out, and I was genuinely delighted by the vigorous give-and-take in those sessions.

Even if definitive statements on these subjects were possible, what follows is not such. My objective is much more modest. I hope only to trace my own thinking and understanding of the subject in the hopes that it will stimulate others to go further, and perhaps through my errors-I hope not to have made many, but it was inevitable that I would-new insights will emerge.

• Carl Sagan Glasgow, Scotland October 14,1985

One

NATURE AND WONDER: A RECONNAISSANCE OF HEAVEN

The truly pious must negotiate a difficult course between the

precipice of godlessness and the marsh of superstition.

• Plutarch •

Certainly both extremes are to be avoided, except what are they? What is godlessness? Does not the concern to avoid the 'precipice of godlessness' presuppose the very issue that we are to discuss? And what exactly is superstition? Is it just, as some have said, other people's religion? Or is there some standard by which we can detect what constitutes superstition?

For me, I would say that superstition is marked not by its pretension to a body of knowledge but by its method of seeking truth. And I would like to suggest that superstition is very simple: It is merely belief without evidence. The question of what constitutes evidence in this interesting subject, I will try to address. And I will return to this question of the nature of evidence and the need for skeptical thinking in theological inquiry. The word 'religion' comes from the Latin for 'binding together,' to connect that which has been sundered apart. It's a very interesting concept. And in this sense of seeking the deepest interrelations among things that superficially appear to be sundered, the objectives of religion and science, I believe, are identical or very nearly so. But the question has to do with the reliability of the truths claimed by the two fields and the methods of approach.

By far the best way I know to engage the religious sensibility, the sense of awe, is to look up on a clear night. I