How Do We Know That

My Third Maxim Was To Try Always To Conquer Myself Rather Than Fortune, And To Change My Desires Rather Than The Order Of The World, And Generally To Accustom Myself To Believing That There Is Nothing Entirely In Our Power Except Our Thoughts, So That After We Have Done Our Best Regarding Things External To Us, Everything In Which We Do Not Succeed Is For Us Absolutely Impossible.

The Principal Effect Of The Passions Is That They Incite And Persuade The Mind To Will The Events For Which They Prepared The Body.

There Is Nothing So Strange And So Unbelievable That It Has Not Been Said By One Philosopher Or Another.

Now Therefore, That My Mind Is Free From All Cares, And That I Have Obtained For Myself Assured Leisure In Peaceful Solitude, I Shall Apply Myself Seriously And Freely To The General Destruction Of All My Former Opinions.

Omnia Apud Me Mathematica Fiunt.