An extremely rare copy of Sir Isaac Newton’s seminal work in physics and astronomy is expected to sell for upwards of $1.5 million – as the most valuable item in a Christies auction of 400 books and manuscripts.

Newton’s Principia goes on the block December 14th in New York.

In the copy of his 1687 treatise, Newton laid out his three laws of motion – the same ones most of us learned in high school physics.

He also presented his theory of gravity: that the forces keeping the planets in orbit and our feet on the ground are the same – and not separate.

A copy of Principia given to King James II – sold for $2.5 million in 2013.