“The Cosmos is all that is or ever was or ever will be.”

The author uses the term both as a scientific statement of fact—indeed, the cosmos is where all known life resides—and as a metaphor. The cosmos is a place infinitely larger than the Earth, both imaginatively and literally. It is also a way in which humanity can understand the small planet on which they live, through comparison and knowledge.

“Finally, at the end of all our wanderings, we return to out tiny, fragile, blue-white world, lost in a cosmic ocean vast beyond our most courageous imaginings.”

The author frames the book as a metaphorical cosmic voyage, headed out into the universe before returning to Earth. The Earth is contrasted with the vast distances and mysteries of the larger cosmos. In this way, both the planet humanity calls home and its place in the universe are illuminated and understood in new ways.

“But, as Darwin and Wallace showed, there is another way equally appealing, equally human, and far more compelling: natural selection, which makes the music of life more beautiful as the aeons pass.”

The author respects the religions and cultures of Earth, as the opening quotations of all of the chapters show. However, he also emphasizes the importance of science as a way of understanding the world and the cosmos. Here, he suggests that evolution not only explains how life comes about and adapts on Earth, but also gives us a way to grasp the fundamental poetry of such life. The “music of life” is played to the harmony of the cosmos, in his