First Of All, We Must Note That

Of All Things Visible, The Highest Is The Heaven Of The Fixed Stars.

So If The Worth Of The Arts Were Measured By The Matter With Which They Deal, This Art-which Some Call Astronomy, Others Astrology, And Many Of The Ancients The Consummation Of Mathematics-would Be By Far The Most Outstanding. This Art Which Is As It Were The Head Of All The Liberal Arts And The One Most Worthy Of A Free Man Leans Upon Nearly All The Other Branches Of Mathe Matics. Arithmetic, Geometry, Optics, Geodesy, Mechanics, And Whatever Others, All Offer Themselves In Its Service.

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.

Those Things Which I Am Saying Now May Be Obscure, Yet They Will Be Made Clearer In Their Proper Place.

For I Am Not So Enamoured Of My Own Opinions That I Disregard What Others May Think Of Them.