There is probably no one who has a deeper understanding of life’s biochemical basis than Sir Francis Crick. In 1962, he won the Nobel Prize in Medicine, along with J. D. Watson and M. H. F. Wilkins, for breakthrough studies on the molecular structure of DNA. Just four years later he published this collection of popular lectures in which he explained the importance of this discovery in layperson’s terms and emphasized its wide-reaching implications. Though written forty years ago, this succinct, lucid explication of the scientific facts remains the perfect primer for the lay reader curious about the ongoing biological revolution and is amazingly prescient in light of recent developments. Beginning with a critique of “vitalism,” the notion that an intangible life force beyond the grasp of biology distinguishes living organisms from inanimate things, Crick argues that in all likelihood the complex mechanisms of DNA, RNA, and protein synthesis fully explain the phenomenon of life. While admitting that many details are uncertain and much remains unknown about the origins of life, he nonetheless maintains that chance mutations over time, in conjunction with the law of natural selection, offer the most rational explanation of the evolution of life on earth from inorganic precursors. Although few speak of vitalism today, the controversy that Crick addresses is still with us in the form of intelligent design, which suggests that biochemistry and evolution alone do not sufficiently explain the uniqueness of life. In his second lecture Crick explores the borderline between the organic and inorganic, presenting an elegantly clear description of DNA’s basic structure and function in relation to RNA and myriad enzymes. In the final lecture, “The Prospect Before Us,” he anticipates events and trends that have in fact come to pass in the past four decades: the increasing use of computer technology and robotics in mind-brain research, explorations into right-side vs. left-side uses of the brain, controversies surrounding the existence of the soul, the dead end of ESP investigations, and above all the daunting challenges of explaining consciousness in completely scientific terms. Of Molecules and Men is a fascinating, still-very-relevant discussion of many crucially important issues in life science.