We Have Become Makers Of Our Fate

I Think That We Shall Have To Get Accustomed To The Idea That We Must Not Look Upon Science As A 'body Of Knowledge,' But Rather As A System Of Hypotheses; That Is To Say, As A System Of Guesses Or Anticipations Which In Principle Cannot Be Justified, But With Which We Work As Long As They Stand Up To Tests, And Of Which We Are Never Justified In Saying That We Know They Are 'true' Or 'more Or Less Certain' Or Even 'probable.'

Optimism Is A Duty. The Future Is Open. It Is Not Predetermined. No One Can Predict It, Except By Chance. We All Contribute To Determining It By What We Do. We Are All Equally Responsible For Its Success.

Every Discovery Contains An Irrational Element Or A Creative Intuition.

To Give A Causal Explanation Of An Event Means To Deduce A Statement Which Describes It, Using As Premises Of The Deduction One Or More Universal Laws, Together With Certain Singular Statements, The Initial Conditions ... We Have Thus Two Different Kinds Of Statement, Both Of Which Are Necessary Ingredients Of A Complete Causal Explanation.

Science Does Not Rest Upon Solid Bedrock. The Bold Structure Of Its Theories Rises, As It Were, Above A Swamp. It Is Like A Building Erected On Piles. The Piles Are Driven Down From Above Into The Swamp, But Not Down To Any Natural Or 'given' Base; And If We Stop Driving The Piles Deeper, It Is Not Because We Have Reached Firm Ground. We Simply Stop When We Are Satisfied That The Piles Are Firm Enough To Carry The Structure, At Least For The Time Being.