“The blood of a unicorn will keep you alive, even if you are an inch from death, but at a terrible price. You have slain something pure and defenseless to save yourself, and you will have but a half-life, a cursed life, from the moment the blood touches your lips.”
Firenze the centaur to Harry Potter, Harry Potter and the Philosopher’s Stone, J. K. Rowling
“Stories about the medicinal values of a unicorn’s horn, especially that it is an antidote to poisons, may have originated from similar Asian beliefs about the rhinoceros horn.” Konrad Gesner, Historiae Animalium, 1551
Harry Potter's World
In Harry Potter, unicorns are considered sacred and pure creatures that should only be used in magic without harming the animal in any way. The evil Lord Voldemort disregards such warnings and cruelly slaughters several unicorns for their magical life-giving blood, exposing his disregard for the natural world. Although Voldemort learns about the creatures that can benefit him, he ignores and underestimates the value of those that do not. Harry, on the other hand, is open to all that the natural world has to offer, a trait that ultimately helps the young wizard end Lord Voldemort's violent reign.
“… Sirens, Nereides, or mere-maides, who (according to Pliny) have the faces of women, and scaley bodies, yea where as they have the shape of man; neither yet can the forementioned wed confusion and conjuction of seeds take any place here, for, as we lately said, they consist of their owne proper nature.” The Workes of Ambrose Parey, translated out of Latine, 1634
The History of Science
The influential surgeon Ambroise Paré, noted for using less invasive procedures than his contemporaries, believed that studying nature was important to understanding the world. Paré believed that everything on earth had been perfectly created, including the odd and unusual creatures he often wrote about in his works. For example, although not wholly convinced the animal existed, the surgeon included unicorns in his writings because of the numerous accounts of sightings and the creature's purported medicinal uses. Unicorn horn, such as that of the bihorn species Paré described, was commonly believed to neutralize poisons and many apothecaries claimed to stock it.