From the intro to Marlowe’s Tragical History of Doctor Faustus (Clarendon Press, 1887):

“In the Middle Ages, two branches of study, the votaries of which were necessarily to a large extent groping in the dark or unsteadily moving in the twilight, were specially adapted to attract enquiring minds, and to excite the suspicions of the ignorant. These were astrology, which in the terminology of the Middle Ages included what we call astronomy, but which also occupied itself with speculations on the supposed influences of the heavenly bodies upon the inhabitants of the earth and their destinies, as well as with their actual or supposed influences upon the earth itself; and alchemy or chemistry, the speculative part of which treated of the production of all things out of the elements, while the practical part sought to rival or outdo nature in the production of colours and of many other things, but more especially of precious metals.

The connexion which both these sciences thus assumed with common life, with its chief events and most cherished objects, could not fail to impress and excite the wild imagination of common men; and the isolation in which these studies have to be carried on, the loneliness of the observatory and the laboratory, added a peculiar element of mystery.

In these and in other sciences the instruments used or invented by their professors seemed a machinery of a more than human character and origin. All these studies and their appliances were regarded as magic and as appliances of magic by the vulgar, who could not, like philosophic minds, distinguish the mighty powers of nature and the still mightier powers of art which uses nature as its instrument, from that which passes beyond the powers of nature and art, and is therefore either superhuman, or fiction and imposture..”

Marlowe’s Tragical History of Doctor Faustus: Greene : Honourable History of Friar Bacon and Friar Bungay, Clarendon Press series. Christopher Marlowe. Edition 2. Clarendon Press, 1887.

Download the PDF at http://ia700402.us.archive.org/18/items/oldenglishdramas00warduoft/oldenglishdramas00warduoft.pdf

…Or see it at Google Books:

https://books.google.ca/books?id=BLc8AAAAYAAJ