From Dwight Eisenhower's farewell address:

 ...As we peer into society's future, we -- you and I, and our government --must avoid the impulse to live only for today, plundering for our own ease and convenience the precious resources of tomorrow.  We cannot mortgage the material assets of our grandchildren without risking the loss also of their political and spiritual heritage.  We want democracy to survive for all generations to come, not to become the insolvent phantom of tomorrow.