Personally, People Know Themselves Very Poorly.

A Colour Is A Physical Object As Soon As We Consider Its Dependence, For Instance, Upon Its Luminous Source, Upon Other Colours, Upon Temperatures, Upon Spaces, And So Forth.

I Know Of Nothing More Terrible Than The Poor Creatures Who Have Learned Too Much. Instead Of The Sound Powerful Judgement Which Would Probably Have Grown Up If They Had Learned Nothing, Their Thoughts Creep Timidly And Hypnotically After Words, Principles And Formulae, Constantly By The Same Paths. What They Have Acquired Is A Spider's Web Of Thoughts Too Weak To Furnish Sure Supports, But Complicated Enough To Provide Confusion.

Mathematics May Be Defined As The Economy Of Counting. There Is No Problem In The Whole Of Mathematics Which Cannot Be Solved By Direct Counting.

Without Renouncing The Support Of Physics, It Is Possible For The Physiology Of The Senses, Not Only To Pursue Its Own Course Of Development, But Also To Afford To Physical Science Itself Powerful Assistance.

Strange As It May Sound, The Power Of Mathematics Rests On Its Evasion Of All Unnecessary Thought And On Its Wonderful Saving Of Mental Operations.