The Principia

Newton's book, Philosophiae naturalis principia mathematica, often called Principia for short, was completed by April 1686 and is one of the greatest pieces of scientific literature ever written. Much credit is deserved to Edmond Halley as his initial visit to Cambridge in the fall of 1684 reminded Newton of the work that needed to be completed regarding celestial mechanics. This visit prompted the writing of De motu and quickly lead to the writing of Principia (Cropper 30).

The Principia Title Page

http://www.arm.ac.uk/history/hist_pics.html

Diagram showing the Diffraction of Light

http://www.arm.ac.uk/history/hist_pics.html
Although a groundbreaking piece of literature, the Principia is one of the most incomprehensible books ever written. In about 500 pages and 340 complicated diagrams, Newton proves his arguments with the use of formally presented propositions with demonstrations. To understand the arguments explained in the book, the reader must comprehend each proposition in sequence (Cropper 31).

Another problem that renders the Principia very difficult for the modern reader is that Newton chose to write the book in ancient geometrical style. This style was preferred by Newton not only because it represented the language of the "ancients," but also because the fluxion language (calculus) he developed had not yet been published. In some aspects, the Principia, along with other ground-breaking scientific literature, was written to be more admired than read (Cropper 30-31).