John Milton was born in 1608, eight years after Giordano Bruno had been burnt at the stake and two years before Galileo’s first discoveries with the telescope were published in Sidereus Nuncius. John Dee, that remarkable figure of Renaissance England, died the year Milton was born, but when he was a small boy, Thomas Harriot and the Northumberland circle1 were still conducting experiments in alchemy and magic while Harriot was also engaged in telescopic observations in England at the same time as Galileo. The year 1614, when Milton was six, was a critical one in which Isaac Casaubon’s dating of the Hermetica was announced, an event described by Yates as “a watershed separating the Renaissance world from the modern world,”2 and the controversial Rosicrucian texts first appeared. The impact of these incidents that happened during Milton’s childhood continued to reverberate throughout Britain and Europe for a considerable period of time. The late 1620s, Milton’s university years, witnessed growing debate about the admissibility of the new astronomy into the university curriculum. The 1630s, the period of his self-education at Horton and Hammersmith, was marked by intense speculation regarding the scientific and millennial implications of the new stars of 1572 and 1604.