I Think; Therefore I Am.

Give Me Extension And Motion And I Will Construct The Universe.

So Far, I Have Been A Spectator In This Theater Which Is The World, But I Am Now About To Mount The Stage, And I Come Forward Masked.

When I Consider This Carefully, I Find Not A Single Property Which With Certainty Separates The Waking State From The Dream. How Can You Be Certain That Your Whole Life Is Not A Dream?

And As It Is The Most Generous Souls Who Have Most Gratitude, It Is Those Who Have Most Pride, And Who Are Most Base And Infirm, Who Most Allow Themselves To Be Carried Away By Anger And Hatred.

Some Years Ago I Was Struck By The Large Number Of Falsehoods That I Had Accepted As True In My Childhood, And By The Highly Doubtful Nature Of The Whole Edifice That I Had Subsequently Based On Them. I Realized That It Was Necessary, Once In The Course Of My Life, To Demolish Everything Completely And Start Again Right From The Foundations If I Wanted To Establish Anything At All In The Sciences That Was Stable And Likely To Last.