Sir Isaac Newton, translated by Andrew Motte. The original Latin is below (according to answers.com, not a copy of the book). I know I could have gone with the objects in motion tend to stay in motion unless acted upon by an outside force, but I find his particular phrasing far more poetic. Newton wrote his famed three laws in The Mathematical Principles of Natural Philosophy, which shows that he considered his work, at least in part, philosophy. It shares many traits of classical philosophy and mathematics, including the use of the word Axiom in the original text. It’s quite evocative if you appreciate science and math literature. For normal people, it’s just an unnecessarily obtuse passage.
Lex I: Corpus omne perseverare in statu suo quiescendi vel movendi uniformiter in directum, nisi quatenus a viribus impressis cogitur statum illum mutare.