2009 marks the bicentennial of Charles Darwin’s birth and the 150th anniversary of the publication of his most famous work, On the Origin of Species. The Ransom Center owns several copies of the first edition, the most interesting being the one sent by Darwin to Sir John Herschel, a famous English scientist of his day, inscribed simply “From the author.”

Darwin identified Herschel in the second sentence of the Origin as “one of our greatest philosophers.” Early in his career, Darwin knew that the elder scientist had defined “the species question”—or in Herschel’s words, “that mystery of mysteries” —as being the central one for the new science of biology (the term wasn’t widely used until mid-century). In 1836, the young scientist,…