First Of All, We Must

Since, Then, There Is No Objection To The Mobility Of The Earth, I Think It Must Now Be Considered Whether Several Motions Are Appropriate For It, So That It Can Be Regarded As One Of The Wandering Stars. For The Fact That It Is Not The Centre Of All Revolutions Is Made Clear By The Apparent Irregular Motion Of The Wandering Stars, And Their Variable Distances From The Earth, Which Cannot Be Understood In A Circle Having The Same Centre As The Earth.

To Know The Mighty Works Of God, To Comprehend His Wisdom And Majesty And Power; To Appreciate, In Degree, The Wonderful Workings Of His Laws, Surely All This Must Be A Pleasing And Acceptable Mode Of Worship To The Most High, To Whom Ignorance Cannot Be More Grateful Than Knowledge.

In The First Book I Shall Describe All The Positions Of The Spheres, Along With The Motions Which I Attribute To The Earth, So That The Book Will Contain As It Were The General Structure Of The Universe. In The Remaining Books I Relate The Motions Of The Remaining Stars, And All The Spheres, To The Mobility Of The Earth, So That It Can Be Thence Established How Far The Motions And Appearances Of The Remaining Stars And Spheres Can Be Saved, If They Are Referred To The Motions Of The Earth.

The Two Revolutions, I Mean The Annual Revolutions Of The Declination And Of The Centre Of The Earth, Are Not Completely Equal; That Is The Return Of The Declination To Its Original Value Is Slightly Ahead Of The Period Of The Centre. Hence It Necessarily Follows That The Equinoxes And Solstices Seem To Anticipate Their Timing, Not Because The Sphere Of The Fixed Stars Moves To The East, But Rather The Equatorial Circle Moves To The West, Being At An Angle To The Plane Of The Ecliptic In Proportion To The Declination Of The Axis Of The Terrestrial Globe.

When, Therefore, I Had Long Considered This Uncertainty Of Traditional Mathematics, It Began To Weary Me That No More Definite Explanation Of The Movement Of The World-machine Established In Our Behalf By The Best And Most Systematic Builder Of All, Existed Among The Philosophers Who Had Studied So Exactly In Other Respects The Minutest Details In Regard To The Sphere.