At Rest, However, In The Middle Of

Perhaps There Will Be Prattlers Who, Although Completely Ignorant Of Mathematics, Nevertheless Take It Upon Themselves To Pass Judgment On Mathematical Questions, And On Account Of Some Passage In Scripture, Badly Distorted To Their Purpose, Will Dare To Censure And Assail What I Have Presented Here.

I Shall Now Recall To Mind That The Motion Of The Heavenly Bodies Is Circular, Since The Motion Appropriate To A Sphere Is Rotation In A Circle.

Yet The Widespread Planetary Theories, Advanced By Ptolemy And Most Other Astronomers, Although Consistent With The Numerical Data, Seemed Likewise To Present No Small Difficulty. For These Theories Were Not Adequate Unless They Also Conceived Certain Equalizing Circles, Which Made The Planet Appear To Move At All Times With Uniform Velocity Neither On Its Deferent Sphere Nor About Its Own Epicycle's Center.

I Can Easily Conceive, Most Holy Father, That As Soon As Some People Learn That In This Book Which I Have Written Concerning The Revolutions Of The Heavenly Bodies, I Ascribe Certain Motions To The Earth, They Will Cry Out At Once That I And My Theory Should Be Rejected.

In First Place We Must Observe That The Universe Is Spherical. This Is Either Because That Figure Is The Most Perfect, As Not Being Articulated, But Whole And Complete In Itself; Or Because It Is The Most Capacious And Therefore Best Suited For That Which Is To Contain And Preserve All Things.