[t]he Atoms Or Elementary Particles Themselves Are

Both Matter And Radiation Possess A Remarkable Duality Of Character, As They Sometimes Exhibit The Properties Of Waves, At Other Times Those Of Particles. Now It Is Obvious That A Thing Cannot Be A Form Of Wave Motion And Composed Of Particles At The Same Time - The Two Concepts Are Too Different

A Consistent Pursuit Of Classical Physics Forces A Transformation In The Very Heart Of That Physics.

The Positivists Have A Simple Solution: The World Must Be Divided Into That Which We Can Say Clearly And The Rest, Which We Had Better Pass Over In Silence. But Can Anyone Conceive Of A More Pointless Philosophy, Seeing That What We Can Say Clearly Amounts To Next To Nothing? If We Omitted All That Is Unclear, We Would Probably Be Left Completely Uninteresting And Trivial Tautologies.

If Nature Leads Us To Mathematical Forms Of Great Simplicity And Beauty - By Forms I Am Referring To Coherent Systems Of Hypothesis, Axioms, Etc. - To Forms That No One Has Previously Encountered, We Cannot Help Thinking That They Are "true," That They Reveal A Genuine Feature Of Nature... You Must Have Felt This Too: The Almost Frightening Simplicity And Wholeness Of Relationships Which Nature Suddenly Spreads Out Before Us And For Which None Of Us Was In The Least Prepared.

It Seems Sensible To Discard All Hope Of Observing Hitherto Unobservable Quantities, Such As The Position And Period Of The Electron... Instead It Seems More Reasonable To Try To Establish A Theoretical Quantum Mechanics, Analogous To Classical Mechanics, But In Which Only Relations Between Observable Quantities Occur.