When it appeared in 1670, Baruch Spinoza’s Theological-Political Treatise was denounced as the most dangerous book ever published – “godless,” “full of abominations,” “a book forged in hell…by the devil himself.” Religious and secular authorities saw it as a threat to faith, social and political harmony, and everyday morality, and its author was almost universally regarded as a religious subversive and political radical who sought to spread atheism throughout Europe. Steven Nadler tells the fascinating story of this extraordinary book: its radical claims and their background in the philosophical, religious, and political tensions of the Dutch Golden Age, as well as the vitriolic reaction these ideas inspired.