New Ideas Often Need Old Buildings.

Beneficent Spirals, Operating By Benign Feedback, Mean That Everything Needful Is Not Required At Once: Each Individual Improvement Is Beneficial For The Whole

A Border--the Perimeter Of A Single Massive Or Stretched-out Use Of Territory--forms The Edge Of An Area Of 'ordinary' City. Often Borders Are Thought Of As Passive Objects, Or Matter-of-factly Just As Edges. However, A Border Exerts An Active Influence.

Cities Need Old Buildings So Badly It Is Probably Impossible For Vigorous Streets And Districts To Grow Without Them.... For Really New Ideas Of Any Kind--no Matter How Ultimately Profitable Or Otherwise Successful Some Of Them Might Prove To Be--there Is No Leeway For Such Chancy Trial, Error And Experimentation In The High-overhead Economy Of New Construction. Old Ideas Can Sometimes Use New Buildings. New Ideas Must Use Old Buildings.

What If We Fail To Stop The Erosion Of Cities By Automobiles? ... In That Case America Will Hardly Need To Ponder A Mystery That Has Troubled Men For Millennia. What Is The Purpose Of Life? For Us, The Answer Will Be Clear, Established And For All Practical Purposes Indisputable. The Purpose Of Life Is To Produce And Consume Automobiles.

In Trading With Each Other Cities Can't Be In Too Different Stages Of Development, And They Can't Copy One Another. Backward Cities, Or Younger Cities, Or Newly Forming Cities In Supply Regions, Have To Develop To A Great Extent On One Another's Shoulders. This Is One Of The Terrible Things About Empires. Empires Want Them Only To Trade With The Empire, Which Doesn't Help Them At All. It's Just A Way Of Exploiting Them.