The Fifth Miracle: The Search for the Origin and Meaning of Life by Paul Davies Search Amazon for other books by or about Paul Davies. Rating: Reviewed by: David Smillie

You can't fault Paul Davies for a lack of gumption. Anyone who'd subtitle his latest book, "the search for the origin and meaning of life" isn't in need of any assertiveness training courses.

When I first picked up the book, I thought, "Yeesh, a physicist, writing about the origins of life. Wouldn't that be more the work of a molecular biologist?" But as I read on, I was gradually taken in by Davies spell.

And that's saying something. If, five years ago, you'd told me I'd take the following ideas seriously, I'd have laughed nervously and edged away in anon-threatening manner. Here are Davies' ideas in a nutshell (no pun intended):

1) Life may have existed on Mars.
2) Life may still exist on Mars.
3) Life on earth may have arisen in space and migrated here (panspermia).
4) The "natural" home for life on earth may be in the hot depths of the crust, kilometres beneath the surface.

As I say, five years ago, those ideas would have been heresy. But it's been an interesting five years. The (in)famous Martian meteorite, the discovery of tiny, primitive forms of life deep within the earth, life thriving around hydrothermal vents, the discovery of intricate chemical reactions happening in space ... well, it's been fun. And Davies takes full advantage of living in such "interesting times".

Davies makes a thoughtful (if not always persuasive) case for his views on the origins of life. And I found it a really enjoyable read. If you're at all interested in where life came from, or whether there might be life "out there" this is a great book to begin with. Davies is an excellent writer with some fascinating ideas and a great style:

"In a subject supercharged with such significance, lack of agreement is unsurprising. Some scientists regard life as a bizarre chemical freak, unique in the universe, whereas others insist that it is the expected product of felicitous natural laws. If the magnificent edifice of life is the consequence of a random and purely incidental quirk of fate, as the French biologist Jacques Monod claimed, we must surely find common cause with his bleak atheism, so eloquently expressed in these words: "The ancient covenant is in pieces: man at last knows that he is alone in the unfeeling immensity of the universe, out of which he has emerged only by chance. Neither his destiny nor his duty have been written down." But if it transpires that life emerged more or less on cue as part of the deep lawfulness of the cosmos -- if it is scripted into the great cosmic drama in a basic manner -- it hints at a universe with a purpose. In short, the origin of life is the key to the meaning of life."

And while I might not agree with all his ideas ... ask me again in five years