Isaac Newton's work laid the groundwork for modern engineering. Isaac Newton was a physics, astronomer, theologian, alchemist and mathematician at the turn of the 18th century. His Philosophiæ Naturalis Principia Mathematica, published in 1687, is considered to be the most influential book in the history of science. It laid the groundwork for the modern subject of calculus. Originally published in 1733, Observations Upon The Prophecies Of Daniel is more than an interpretation of some prophecies contained in the Bible. It also reveals Newton's knowledge of many aspects of history and the first followers of Christ. This is one of two religious tracts written by Newton.