To derive two or three general Principles of Motion from Phænomena, and afterwards to tell us how the Properties and Actions of all corporeal Things follow from those manifest Principles, would be a very great step in Philosophy.

This thing is but a puny imitation of a much grander system whose laws you know, and I am not able to convince you that this mere toy is without a designer or maker; yet you profess to believe that the great original from which the design is taken has come into being without either designer or maker! Now tell me by what sort of reasoning do you reach such an incongruous conclusion?

What goes up must come down.

Against filling the Heavens with fluid Mediums, unless they be exceeding rare, a great Objection arises from the regular and very lasting Motions of the Planets and Comets in all manner of Courses through the Heavens.

We are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances.

Sir Isaac Newton was asked how he discovered the law of gravity. He replied, "By thinking about it all the time.

God is able to create particles of matter of several sizes and figures and perhaps of different densities and forces, and thereby to vary the laws of nature, and make worlds of several sorts in several parts of the Universe.