I have presented principles of philosophy that are not, however, philosophical but strictly mathematical-that is, those on which the study of philosophy can be based. These principles are the laws and conditions of motions and of forces, which especially relate to philosophy.
Isaac NewtonTherefore to the same natural effects we must, as far as possible, assign the same causes.
Isaac NewtonMy Design in this Book is not to explain the Properties of Light by Hypotheses, but to propose and prove them by Reason and Experiments: In order to which, I shall premise the following Definitions and Axioms.
Isaac NewtonWhat Descartes did was a good step. You have added much several ways, and especially in taking the colours of thin plates into philosophical consideration. If I have seen a little further it is by standing on the shoulders of Giants.
Isaac NewtonAll material Things seem to have been composed of the hard and solid Particles ... variously associated with the first Creation by the Counsel of an intelligent Agent. For it became him who created them to set them in order: and if he did so, it is unphilosophical to seek for any other Origin of the World, or to pretend that it might arise out of a Chaos by the mere Laws of Nature.
Isaac Newton