We should be wary therefore what persecution we raise against the living labours of public men, how we spill that seasoned life of man, preserved and stored up in books; since we see a kind of homicide may be thus committed, sometimes a martyrdom, and if it extend to the whole impression, a kind of massacre; whereof the execution ends not in the slaying of an elemental life, but strikes at that ethereal and fifth essence, the breath of reason itself, slays an immortality rather than a life.

John Milton, in the Areopagitica, 1644