“THEREFORE does this apple fall perpendicularly, or toward the centre. If matter thus draws matter, it must be in proportion of its quantity. Therefore the apple draws the earth, as well as the earth draws the apple.”

And thus by degrees, he began to apply this property of gravitation to the motion of the earth, and of the heavenly bodies: to consider their distances, their magnitudes, their periodical revolutions: to find out, that this property, conjointly with a progressive motion impressed on them in the beginning, perfectly solved their circular courses; kept the planets from falling upon one another, or dropping all together into one centre. And thus he unfolded the Universe. This was the birth of those amazing discoveries, whereby he built philosophy on a solid foundation, to the astonishment of all Europe.