In All The Works On Pedagogy That

...mathematics Is Distinguished From All Other Sciences Except Only Ethics, In Standing In No Need Of Ethics. Every Other Science, Even Logic, Especially In Its Early Stages, Is In Danger Of Evaporating Into Airy Nothingness, Degenerating, As The Germans Say, Into An Arachnoid Film, Spun From The Stuff That Dreams Are Made Of. There Is No Such Danger For Pure Mathematics; For That Is Precisely What Mathematics Ought To Be.

If Man Were Immortal He Could Be Perfectly Sure Of Seeing The Day When Everything In Which He Had Trusted Should Betray His Trust, And, In Short, Of Coming Eventually To Hopeless Misery. He Would Break Down, At Last, As Every Good Fortune, As Every Dynasty, As Every Civilization Does. In Place Of This We Have Death.

Every Man Is Fully Satisfied That There Is Such A Thing As Truth, Or He Would Not Ask Any Question.

Three Elements Go To Make Up An Idea. The First Is Its Intrinsic Quality As A Feeling. The Second Is The Energy With Which It Affects Other Ideas, An Energy Which Is Infinite In The Here-and-nowness Of Immediate Sensation, Finite And Relative In The Recency Of The Past. The Third Element Is The Tendency Of An Idea To Bring Along Other Ideas With It.

It Is Not Knowing, But The Love Of Learning, That Characterizes The Scientific Man.