David Downing has achieved something quite remarkable with this book: He has succeeded in making a thoroughly researched, philosophically-heavy, intellectual biography an engrossing read.
This is by no means a CS Lewis biography. It is, rather, a biography of Lewis' mind before, during and immediately after his conversion to a belief in Christ. Downing explores several avenues of Lewis' philosophical quest, none more so than his unceasing pursuit of "Joy." This pursuit leads Lewis, and the reader, through all stages of Lewis' intellectual and religious development--from atheistic materialism to the occult to philosophical Idealism to pantheism and finally to Christ. Along the way, the reader is introduced to many of Lewis' spiritual, philosophical and intellectual mentors.
This could have easily (almost predictably) become a dry, excruciatingly dull narrative with all the readability of a poorly-written freshman philosophy text. Instead, it is a true page-turner as Downing relates Lewis' intellectual pursuit of the aforementioned concepts. One-by-one the philosophical challengers to Christianity are discovered, honestly scrutinized, shown be intellectually wanting, and ultimately rejected.
Don't be put off by the centrality of philosophical discussion in this book. It is an easy read and it is actually quite fun to see how Lewis used his monumental intellect to punch irreparable holes in philosophical concepts considered sacrosanct by preening, self-important atheistic egotists. Though an atheist during his teens and twenties, Lewis never stopped pursuing iron-clad intellectual arguments which would quench his thirst for "Joy." His intellectual honesty never allowed him to be satisfied with answers which rested on shaky philosophical ground. And part of his restless pursuit of "Joy" was his search for a firm and unassailable theoretical foundation on which he could build a consistent belief system.
Bravo to Mr. Downing for writing this marvelous book. Perhaps no other work allows us to peer more deeply into the mind of this magnificent intellect.