At the time young Charles Darwin set out on his ground-breaking 1831 voyage aboard the HMS Beagle, he himself was an intelligent design supporter, saying he ""hardly ever admired a book more"" than William Paley's Natural Theology; or, Evidences of the Existence and Attributes of the Deity. Author and professor Thomson (Before Darwin: Reconciling God and Nature) delivers a lively account of how this naive young student became the iconoclastic bearer of ""the most dangerous idea of the past two hundred years."" The grandson of eminent free-thinker Erasmus Darwin as well as a medical and theology student, Darwin was well-versed in the ""raging controversy"" over the origins of Earth and it inhabitants. The suggestion that ""life had arisen without God's intervention"" was at the time ""almost unmentionable""; hotly debated topics included the frequency of God's intervention (a one-time event or an everyday thing?), and whether Earth's history is cyclical or progressive. Darwin's first and abiding love was natural history (his extensive beetle collection earned him his ""naturalist"" position aboard the Beagle) and led to his era-defining theories. Drawing on his letters, diary entires and autobiographical work as well as his public intellectual struggles, Thomson's angle on Darwin's early life is fresh and vivid.