List of Galileo Galilei Quotes

When The Moon Is Ninety Degrees Away From The Sun It Sees But Half The Earth Illuminated (the Western Half). For The Other (the Eastern Half) Is Enveloped In Night. Hence The Moon Itself Is Illuminated Less Brightly From The Earth, And As A Result Its Secondary Light Appears Fainter To Us.

Surely It Is A Great Thing To Increase The Numerous Host Of Fixed Stars Previously Visible To The Unaided Vision, Adding Countless More Which Have Never Before Been Seen, Exposing These Plainly To The Eye In Numbers Ten Times Exceeding The Old And Familiar Stars.

Their Vain Presumption Of Knowing All Can Take Beginning Solely From Their Never Having Known Anything; For If One Has But Once Experienced The Perfect Knowledge Of One Thing, And Truly Tasted What It Is To Know, He Shall Perceive That Of Infinite Other Conclusions He Understands Not So Much As One.

Spots Are On The Surface Of The Solar Body Where They Are Produced And Also Dissolved, Some In Shorter And Others In Longer Periods. They Are Carried Around The Sun; An Important Occurrence In Itself.

Nothing Physical Which Sense-experience Sets Before Our Eyes, Or Which Necessary Demonstrations Prove To Us, Ought To Be Called In Question (much Less Condemned) Upon The Testimony Of Biblical Passages...

For My Part I Consider The Earth Very Noble And Admirable Precisely Because Of The Diverse Alterations, Changes, Generations, Etc. That Occur In It Incessantly.

Names And Attributes Must Be Accommodated To The Essence Of Things, And Not The Essence To The Names, Since Things Come First And Names Afterwards.

They Seemed To Forget That The Increase Of Known Truths Stimulates The Investigation, Establishment And Growth Of The Arts; Not Their Dimination Or Destruction.

Alas! Your Dear Friend And Servant Galileo Has Been For The Last Month Hopelessly Blind; So That This Heaven, This Earth, This Universe, Which I By My Marvelous Discoveries And Clear Demonstrations Had Enlarged A Hundred Thousand Times Beyond The Belief Of The Wise Men Of Bygone Ages, Henceforward For Me Is Shrunk Into Such A Small Space As Is Filled By My Own Bodily Sensations.

I Therefore Concluded, And Decided Unhesitatingly, That There Are Three Stars In The Heavens Moving About Jupiter, As Venus And Mercury About The Sun; Which At Length Was Established As Clear As Daylight By Numerous Other Observations.

The Number Of The Fixed Stars Which Observers Have Been Able To See Without Artificial Powers Of Sight Up To This Day Can Be Counted. It Is Therefore Decidedly A Great Feat To Add To Their Number, And To Set Distinctly Before The Eyes Other Stars In Myriads, Which Have Never Been Seen Before, And Which Surpass The Old, Previously Known Stars In Number More Than Ten Times.

I Cannot But Be Astonished That Sarsi Should Persist In Trying To Prove By Means Of Witnesses Something That I May See For Myself At Any Time By Means Of Experiment. Witnesses Are Examined In Doutbful Matters Which Are Past And Transient, Not In Those Which Are Actual And Present. A Judge Must Seek By Means Of Witnesses To Determine Whether Peter Injured John Last Night, But Not Whether John Was Injured, Since The Judge Can See That For Himself.