Newtonianism is a philosophical and scientific doctrine inspired by the beliefs and methods of natural philosopher Isaac Newton. While Newton's influential contributions were primarily in physics and mathematics, his broad conception of the universe as being governed by rational and understandable laws laid the foundation for many strands of Enlightenment thought. Newtonianism became an influential intellectual program that applied Newton's principles in many avenues of inquiry, laying the groundwork for modern science (both the natural and social sciences), in addition to influencing philosophy, political thought and theology. Newton's Principia Mathematica, published by the Royal Society in 1687 but not available widely and in English until after his death, is the text generally cited as revolutionary or otherwise radical in the development of science. The three books of Principia, considered a seminal text in mathematics and physics, are notable for their rejection of hypotheses in favor of inductive and deductive reasoning based on a set of definitions and axioms. This method may be contrasted to the Cartesian method of deduction based on sequential logical reasoning, and showed the efficacy of applying mathematical analysis as a means of making discoveries about the natural world. Newton's other seminal work was Opticks, printed in 1704 in Philosophical Transactions of the Royal Society, of which he became president in 1703. The treatise, which features his now famous work on the composition and dispersion of sunlight, is often cited as an example of how to analyze difficult questions via quantitative experimentation. Even so, the work was not considered revolutionary in Newton's time. One hundred years later, however, Thomas Young would describe Newton's observations in Opticks as "yet unrivalled... they only rise in our estimation as we compare them with later attempts to improve on them.