BY WALTER ISAACSON Saturday, December 31, 2005 12:01 a.m.

1. "Einstein's Clocks, Poincaré's Maps" by Peter Galison (Norton, 2003). We've seen much hoopla in 2005 regarding the centennial of Albert Einstein's miracle year, when he published seminal papers on special relativity and the quantum nature of light. Several smart books on Einstein were also published, adding to the growing library of works on this endlessly fascinating man. One particularly interesting approach of writers over the years has been to consider Einstein in tandem with another great genius and compare how their minds worked. Among the best of these is "Einstein's Clocks, Poincaré's Maps" and the four others that follow here. Henri Poincaré, the great polymath, hit on many elements of relativity just before Einstein did, but he did not make the full leap. Mr. Galison describes how Poincaré's study of time zones and Einstein's work in the Swiss patent office examining devices to synchronize clocks may have influenced their scientific thinking. Some scholars feel Mr. Galison goes too far. But this intriguing book provokes us all to wrestle with our own approach to ideas: How do various influences, conscious or not, flow together to produce a new concept?

2. "The Invisible Century: Einstein, Freud, and the Search for Hidden Universes" by Richard Panek (Viking, 2004). They met only once, in 1927, when Einstein was 47 and Freud was 70. The former was at best mildly bemused by the latter's advocacy of psychoanalysis. As Mr. Panek notes, soon after their meeting, Freud wrote to a friend: "He understands as much about psychology as I do about physics, so we had a very pleasant talk." But Mr. Panek also delightfully shows that these two giants of the 20th century shared an intuitive approach to new ideas. Neither settled for merely interpreting data or making inductions based on experiments; instead, they took great conceptual leaps by embracing grand postulates that reconceived old ways of thinking.

3. "Einstein, Picasso: Space, Time, and the Beauty That Causes Havoc" by Arthur I. Miller (Basic Books, 2001).No, no, there's no suggestion here that Einstein's theory of relativity led to the time-and-space contortions of cubism and other modern art. Mr. Miller, however, shows something more subtly fascinating: how both Einstein and Picasso were wrestling with time and space when there was a realization in many fields that these and other classical absolutes could be questioned. The air was charged at the beginning of the century, allowing for creative sparks.

4. "Einstein in Love: A Scientific Romance" by Dennis Overbye (Viking, 2000). This riveting tale of the young Einstein and his first wife, Mileva Maric, is filled with wonderful elements: passion and betrayal, a mysterious lost child, and the grueling and almost successful struggle of a brilliant female physicist to break into a male world. Some have claimed that Maric was a partner in her husband's discovery of relativity. As Mr. Overbye shows, there's no need go that far in order to be awed by this couple's struggle, together and separately.

5. "A World Without Time: The Forgotten Legacy of Gödel and Einstein" by Palle Yourgrau (Basic Books, 2005).Along with Rebecca Goldstein's fine biography, "Incompleteness," Mr. Yourgrau's book should revive interest in the tantalizing logician Kurt Gödel. It also shows how these two men, who each enjoyed the way the other's mind worked, formed a late-life friendship that led Gödel to extend Einstein's theory of time to--and perhaps past--its logical implications. Mr. Isaacson, CEO of the Aspen Institute, is the author of "Benjamin Franklin: An American Life" and is working on a biography of Einstein.