First Of All, We Must Note That

More Stars In The North Are Seen Not To Set, While In The South Certain Stars Are No Longer Seen To Rise.

So Far As Hypotheses Are Concerned, Let No One Expect Anything Certain From Astronomy, Which Cannot Furnish It, Lest He Accept As The Truth Ideas Conceived For Another Purpose, And Depart From This Study A Greater Fool Than When He Entered It.

Although All The Good Arts Serve To Draw Man's Mind Away From Vices And Lead It Toward Better Things, This Function Can Be More Fully Performed By This Art, Which Also Provides Extraordinary Intellectual Pleasure.

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 That We Know What We Know, And To Know That We Do Not Know What We Do Not Know, That Is True Knowledge.